British Journal of Dermatology (1976) 95, 555.
Paroxysmal itching in multiple sclerosis P.O.OSTERMAN Department of Neurology, University Hospital, Uppsala, Sweden Accepted for publication 29 March 1976
SUMMARY
In three women with multiple sclerosis, paroxysmal attacks of itching occurred. There were several similarities between these attacks and other types of paroxysmal phenomena previously described in multiple sclerosis. The attacks were brief, but usually lasted several minutes, they started and ended abruptly, and recurred several times a day. They were controlled effectively by carbamazepine. It is suggested that paroxysmal itching is caused by transversely spreading ephaptic activation of axons within a partially demyelinated lesion in pain-conducting fibre tracts in the central nervous system.
Itching is a rare symptom in neurological diseases. It may occur in herpes zoster and tabes dorsalis (Cairns, 1972). An itching sensation may also occasionally be observed as a sensory symptom in multiple sclerosis (MS) (McAlpine, 1972). The occurrence of paroxysmal attacks of itching in MS, however, seems to have been reported in only one patient previously (Osterman & Westerberg, 1975). This case is reviewed in the present paper (Case 2) together with two additional patients with paroxysmal itching. These three cases have several features in common. CASE REPORTS
Case I. A woman, born in 1922 with no relevant past history. In 1962 she had a period of numbness in both legs and right-sided optic neuritis, and in 1974 another bout of numbness in both legs. Since 1962 Lhermitte's sign (sudden, transient, electric-Uke shocks extending down the arms, trunk and legs on bending the head forward; due to a lesion affecting the posterior colimins of the cervical cord) has been present for long periods. Neurological examination revealed nothing pathological. Agar-gel electrophoresis of the cerebrospinal fluid strengthened the diagnosis of MS. Paroxysmal itching first occurred in 1959, over a period of 2 months, during which time she had numbness in the right thumb. The itching sensation was localized simultaneously to the right thumb, the radial part of the hand and the lateral aspect of the right upper arm. The attacks started with a creeping sensation 'beneath' the skin, followed within seconds by an intense sensation of itching. She clawed and scratched, but without relief. The attacks started and ended abruptly. They lasted 10-15 min and recurred very frequently with only short free intervals in between. Attacks of itching recurred in 1974. The itching sensation was localized to the lateral aspects of the upper arms and the back of the neck. Most often the attacks occurred in the left arm, but sometimes both arms were affected simultaneously. When the itching occurred in the back of the neck the arms were not affected. The patient described the sensation as similar to a midge bite. The attacks started H
555
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P.O.Osterman
and ended abruptly. They lasted about 15 min and at first recurred about twice a week. After 6 months the frequency was one to three a day. Carbamazepine in a dosage of 200-400 mg twice daily was given in two short periods and the attacks disappeared during the treatment. In the autimin of 1975 they recurred. They now started with an itching sensation in the back of the neck, with rapid spreading to the lateral aspect of both upper arms. The itching was intense and frequently woke her up at night. An aching pain was often felt at the same time as the itching. Pinching of the itching area gave rehef for about a minute. The attacks lasted up to 30 min and they recurred up to 10 times a day. Carbamazepine was given in a dosage of 200 mg three times daily and the attacks ceased completely within a day. Case 2. A woman, born in 1940, with undoubted MS since 1962. Lhermitte's sign was present for long periods. Attacks of itching first occurred in 1962. For several months she had attacks of intense itching in the front of both thighs, starting on both sides at the same time. The itching started and ended abruptly and lasted 3-4 min. She sometimes had 15-20 attacks a day, but usually the frequency was lower. After 1967, paroxysmal itching occurred in the hands, with periods of attacks either in ± e right or left hand. Within each period the attacks were always in the same hand. The itching sometimes affected the fingertips, sometimes the palm of the hand, and sometimes the whole hand. On exceptional occasions both the hand and forearm were affected. The itching sensation was described as similar 10 an extremely itching midge bite. The patient could not resist the urge to scratch, although this gave no relief. She scratched with hard brushes, matchboxes and knives. She put her hand in the freezer aind in hot water without relief. The attacks started and ended abruptly and lasted about 3 min. Drying the hands with a towel after washing often precipitated attacks. At most she had 15 attacks a day, but usually the frequency was much lower. The patient was treated with carbamazepine from October 1971, in a dosage of 400 mg three times daily. During this treatment the attacks of itching were less frequent, shorter, and less intense. After 2 months she temporarily discontinued the treatment, and until it was resumed paroxysmal itching recurred several times a day, and was very intense. In the autumn of 1972 no attacks occurred and treatment was stopped. Subsequently there have been only sporadic attacks of slight itching. Case J. A woman, born in 1950, with no relevant past history. In 1972 she had right-sided optic neuritis and subsequently several bouts of numbness and weakness in the legs and arms, and a bout of vertigo. Lhermitte's sign was present for long periods. Neurological examination between the bouts revealed nothing pathological except defective colour vision of the right eye, exaggerated refiexes in the legs and abolished abdominal refiexes. Agar-gel electrophoresis of the cerebrospinal fiuid strengthened the diagnosis of MS. Starting in September 1974, paroxysmal attacks of pain occurred in the ulnar part of both forearms and hands. It usually was of an aching character. The attacks lasted 2-10 min and at most they recurred 50-80 times a day. Carbamazepine 600-800 mg daily and phenytoin 300 mg daily were effective in controlling the paroxysmal pain, although sporadic attacks still occurred during this therapy. Transcutaneous electrical stimulation was tried, but had no effect. After several months the attacks became less severe and recurred less frequently. Paroxysmal itching first occurred in November 1974. The intense itching sensation was localized to both sides of the trunk, in symmetrical areas corresponding to the thoracic spinal segments seven or eight. The attacks occurred on either side, but most often were right-sided. The itching sometimes affected the back, but was more often localized to the front of the trunk near the midline. Three days before the attacks started the patient noticed decreased sensitivity to light touch within the affected area on the right side. Within the affected areas on both sides the application of cold and pinpricking gave a hyperpathic response. The itching started abruptly but ended more gradually.
Paroxysmal itching in multiple sclerosis
557
Sometimes there was a slight burning sensation at the same time. Attacks could be precipitated by light touch within the affected areas. During the attacks application of ice and firm pressure and pinching ofthe itching skin area gave relief for about a minute. The duration of itching was i-io min, and at most she had 20 attacks a day. During carbamazepine treatment (400-800 mg daily) the attacks were less frequent, shorter, and less intense. Treatment with phenytoin (serum level 52 /^mol/l) seemed less effective. Transcutaneous electrical stimulation had no effect. The sensitivity in the affected areas was normalized within 6 months. Sporadic attacks still recurred, however. In the autumn of 1975 the patient had paroxysmal itching localized to the left side of the neck. The attacks occurred during a bout of diminished sensitivity and patches of hyperaesthesia in the body below the head, weakness of the legs and urgency of micturition. Neurological examination during this bout fur±er disclosed signs indicating disorder ofthe pyramidal tracts and ataxia ofthe right arm. The itching sensation was localized within an area, as large as the palm of a hand, in the left side of the neck. Attacks of itching could be precipitated by light touch. Firm pressure and pinching ofthe itching skin area mitigated the itching sensation. The itching was so intense that it disturbed the patient's sleep. The attacks lasted 15-20 min and recurred every 2-30 min. Within the same area occasional attacks of paroxysmal pain also occurred. There were also sporadic attacks of itching within small areas of the right arm. The paroxysmal itching disappeared after i month, concurrent with considerable improvement of the other symptoms. DISCUSSION
The attacks of itching in these three women with multiple sclerosis have several characteristic features in common: (i) The attacks started and ended abruptly. (2) The attacks recurred frequently, usually several times a day. (3) The duration of the attacks was usually several minutes and in no case less than i min. (4) In two cases the itching was localized to an area with numbness and diminished sensitivity. In these cases the distribution of the itching sensation seemed to be segmental (Case i : cervical segment six; Case 3: thoracic segment seven or eight). (5) Two cases (2 and 3) had attacks of itching which could be precipitated by touch and two cases (i and 3) had paroxysmal itching which was relieved by pinching of the itching skin area. (6) In all cases itching attacks occurred on both sides of the body, in symmetrical areas. (7) Carbamazepine was effective against the paroxysmal itching. (8) All three patients had itching attacks in at least two different sites during two different time periods. (9) Lhermitte's sign was present in all cases. (10) Neurological examination between the bouts revealed only minor abnormalities. Paroxysmal symptoms are not infrequent in MS. Twenty-two of 235 patients with undoubted or suspected MS, treated at the Department of Neurology, Uppsala, during an 8-year period, had paroxysmal symptoms during the course of their disease (Osterman & Westerberg, 1975). The most common types of attacks are paroxysmal dysarthria and ataxia, and tonic seizures. Less common are paroxysmal diplopia, paroxysmal akinesia, paroxysmal numbness and paroxysmal pain. The similarities between the different kinds of paroxysmal phenomena in MS—their brevity, their stereotypical appearance in the individual patient, the frequency, the eliciting factors, the effect of phenytoin and carbamazepine—suggest that the same pathogenic mechanism is operative in the various attacks. The findings in some recent studies support the concept that paroxysmal phenomena in MS are caused by transversely spreading ephaptic activation (i.e. activation via an artificial synapse) of axons within a partially demyelinated lesion in fibre tracts somewhere in the central nervous system (Ekbom, Westerberg & Osterman, 1968; Matthews, 1975; Osterman & Westerberg, 1975). Although there are many similarities between the various paroxysmal phenomena in MS, the duration ofthe different types of attacks tends to vary. Attacks of paroxysmal dysarthria and ataxia and of
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P.O.Osterman
paroxysmal diplopia typically are brief, lasting for only a few seconds up to half a minute, and tonic seizures commonly last about half a minute. In contrast, the duration of paroxysmal pain (Espir & Millac, 1970; Matthews, 1975; present study. Case 3) and paroxysmal itching is usually several minutes. It is noteworthy that one patient (Case 3) experienced both paroxysmal pain and paroxysmal itching ivithin the same skin area, which indicates that these two types of attacks may be related. It is generally agreed that the peripheral and central nervous pathways subserving the sensation of itching are the same as, or closely follow, those which convey the sense of pain (Sweet, 1959; Chapman, Goodell & Wolff, i960). The patients often compared the paroxysmal itching to an intensely itching midge bite. The itching sensation was localized 'beneath' the skin and it was sometimes associated with a burning or aching sensation. In the peripheral nerves this type ofitching is considered to be mediated by unmyelinated C-fibres (Chapman et al., i960). Torebjork (1974) recorded C-fibre activity with micro-electrodes from intact sensory fascicles in the human peroneal nerve. He found that sensations produced by cutaneous stimuli inducing intense afferent C-fibre activity were described as 'burning, or delayed pain', whereas stimuli eliciting low frequency activity were often experienced as 'itch, or burning itch'. It is therefore possible that irritative lesions in pain-conducting fibre pathways may cause both paroxysmal pain and paroxysmal itching—differences in impulse patterns determining whether the sensation will be one of itch or of pain. The frequent occurrence of itching iittacks in symmetrical areas on both sides of the body suggests that the irritative lesion in these cases may be located in the spinal cord, affecting the decussating spinothalamic nerve fibres. The occurrence of itching with a segmental distribution in two cases also indicates that paroxysmal itching may have a spinal origin. Carbamazepine is generally considered to be the most valuable drug for treatment of paroxysmal phenomena in MS and it was effective in controlling the paroxysmal itching in all three cases. In itch due to various disorders, transcutaneous electrical nerve stimulation has been reported to be effective in many cases (Carlsson et al., 1975). This was only tried in one ofthe three present cases and had no effect on the paroxysmal itching. Finally, it is worthy of mention that none ofthe patients thought of a connexion between the paroxysmal itching and their neurological disease. Two of them had consulted physicians and general practitioners about the attacks. Furthermore, paroxysmal itching may be one of the earliest symptoms of MS. ];t is therefore conceivable that other patients with paroxysmal itching may consult physicians other than neurologists for their attacks of itching. REFERENCES CAIRNS, :R.J. (1972) The skin and the nervous system. In: Textbook of Dermatology (Ed. by A.J.Rook, D.S. Wilkinson and F.J.Ebling), 2nd edn. Vol. 2, p. 1791. Blackwell Scientific Publications, Oxford. CARLSSOM, C.-A., AUGUSTINSSON, L . - E . , LUND, S. & ROUPE, G . (1975) Electrical transcutaneous nerve stimulation
for relief of itch. Experientia, 31, 191. CHAPMAN, L.F., GOODELL, H . & WOLFF, H.G. (i960) Structures and processes involved in the sensation of itch. In: Advances in Biology of Skin. Cutaneous Innervation (Ed. by W.Montagna), Vol. i, p. 161. Pergamon Press, Oxford. BKBOM, K.A., WESTERBERG, C.-E. & OSTERMAN, P.O. (1968) Focal sensory-motor seizures of spinal origin. Laru;et, i, 67.
ESPIR, M . L . E . & MILLAC, P. (1970) Treatment of paroxysmal disorders in multiple sclerosis with carbamazepine (Tegretol). Journal of Neurology, Neurosurgery, and Psychiatry, 33, 528. MCALPINE, D . (1972) Symptoms and signs. In: Multiple Sclerosis. A Reappraisal (Ed. by D.McAlpine, C E . Lumsden and E.D.Acheson), 2nd edn, p. 132. Williams and Wilkins, Baltimore. MATTHEWS, W.B. (1975) Paroxysmal symptoms in multiple sclerosis. Journal of Neurology, Neurosurgery, and Psychiatry, 38, 617. OSTERMAN, P.O. & WESTERBEHG, C.-E. (1975) Paroxysmal attacks in multiple sclerosis. Brain, 98, 189. SWEET, \S7.H. (1959) Pain. In: Handbook of Physiology. Sect. i. Neurophysiology (Ed. by J.Field, H.W.Magoun and V.E.Hall), Vol. i, p. 459. American Physiological Society, Washington D.C. K, H.E. (1974) Afferent C units responding to mechanical, thermal and chemical stimuli in human nonglabrous skin. Acta Physiologica Scandinavica, 92, 374.
Paroxysmal itching in multiple sclerosis P.O.OSTERMAN Department of Neurology, University Hospital, Uppsala, Sweden Accepted for publication 29 March 1976
SUMMARY
In three women with multiple sclerosis, paroxysmal attacks of itching occurred. There were several similarities between these attacks and other types of paroxysmal phenomena previously described in multiple sclerosis. The attacks were brief, but usually lasted several minutes, they started and ended abruptly, and recurred several times a day. They were controlled effectively by carbamazepine. It is suggested that paroxysmal itching is caused by transversely spreading ephaptic activation of axons within a partially demyelinated lesion in pain-conducting fibre tracts in the central nervous system.
Itching is a rare symptom in neurological diseases. It may occur in herpes zoster and tabes dorsalis (Cairns, 1972). An itching sensation may also occasionally be observed as a sensory symptom in multiple sclerosis (MS) (McAlpine, 1972). The occurrence of paroxysmal attacks of itching in MS, however, seems to have been reported in only one patient previously (Osterman & Westerberg, 1975). This case is reviewed in the present paper (Case 2) together with two additional patients with paroxysmal itching. These three cases have several features in common. CASE REPORTS
Case I. A woman, born in 1922 with no relevant past history. In 1962 she had a period of numbness in both legs and right-sided optic neuritis, and in 1974 another bout of numbness in both legs. Since 1962 Lhermitte's sign (sudden, transient, electric-Uke shocks extending down the arms, trunk and legs on bending the head forward; due to a lesion affecting the posterior colimins of the cervical cord) has been present for long periods. Neurological examination revealed nothing pathological. Agar-gel electrophoresis of the cerebrospinal fluid strengthened the diagnosis of MS. Paroxysmal itching first occurred in 1959, over a period of 2 months, during which time she had numbness in the right thumb. The itching sensation was localized simultaneously to the right thumb, the radial part of the hand and the lateral aspect of the right upper arm. The attacks started with a creeping sensation 'beneath' the skin, followed within seconds by an intense sensation of itching. She clawed and scratched, but without relief. The attacks started and ended abruptly. They lasted 10-15 min and recurred very frequently with only short free intervals in between. Attacks of itching recurred in 1974. The itching sensation was localized to the lateral aspects of the upper arms and the back of the neck. Most often the attacks occurred in the left arm, but sometimes both arms were affected simultaneously. When the itching occurred in the back of the neck the arms were not affected. The patient described the sensation as similar to a midge bite. The attacks started H
555
556
P.O.Osterman
and ended abruptly. They lasted about 15 min and at first recurred about twice a week. After 6 months the frequency was one to three a day. Carbamazepine in a dosage of 200-400 mg twice daily was given in two short periods and the attacks disappeared during the treatment. In the autimin of 1975 they recurred. They now started with an itching sensation in the back of the neck, with rapid spreading to the lateral aspect of both upper arms. The itching was intense and frequently woke her up at night. An aching pain was often felt at the same time as the itching. Pinching of the itching area gave rehef for about a minute. The attacks lasted up to 30 min and they recurred up to 10 times a day. Carbamazepine was given in a dosage of 200 mg three times daily and the attacks ceased completely within a day. Case 2. A woman, born in 1940, with undoubted MS since 1962. Lhermitte's sign was present for long periods. Attacks of itching first occurred in 1962. For several months she had attacks of intense itching in the front of both thighs, starting on both sides at the same time. The itching started and ended abruptly and lasted 3-4 min. She sometimes had 15-20 attacks a day, but usually the frequency was lower. After 1967, paroxysmal itching occurred in the hands, with periods of attacks either in ± e right or left hand. Within each period the attacks were always in the same hand. The itching sometimes affected the fingertips, sometimes the palm of the hand, and sometimes the whole hand. On exceptional occasions both the hand and forearm were affected. The itching sensation was described as similar 10 an extremely itching midge bite. The patient could not resist the urge to scratch, although this gave no relief. She scratched with hard brushes, matchboxes and knives. She put her hand in the freezer aind in hot water without relief. The attacks started and ended abruptly and lasted about 3 min. Drying the hands with a towel after washing often precipitated attacks. At most she had 15 attacks a day, but usually the frequency was much lower. The patient was treated with carbamazepine from October 1971, in a dosage of 400 mg three times daily. During this treatment the attacks of itching were less frequent, shorter, and less intense. After 2 months she temporarily discontinued the treatment, and until it was resumed paroxysmal itching recurred several times a day, and was very intense. In the autumn of 1972 no attacks occurred and treatment was stopped. Subsequently there have been only sporadic attacks of slight itching. Case J. A woman, born in 1950, with no relevant past history. In 1972 she had right-sided optic neuritis and subsequently several bouts of numbness and weakness in the legs and arms, and a bout of vertigo. Lhermitte's sign was present for long periods. Neurological examination between the bouts revealed nothing pathological except defective colour vision of the right eye, exaggerated refiexes in the legs and abolished abdominal refiexes. Agar-gel electrophoresis of the cerebrospinal fiuid strengthened the diagnosis of MS. Starting in September 1974, paroxysmal attacks of pain occurred in the ulnar part of both forearms and hands. It usually was of an aching character. The attacks lasted 2-10 min and at most they recurred 50-80 times a day. Carbamazepine 600-800 mg daily and phenytoin 300 mg daily were effective in controlling the paroxysmal pain, although sporadic attacks still occurred during this therapy. Transcutaneous electrical stimulation was tried, but had no effect. After several months the attacks became less severe and recurred less frequently. Paroxysmal itching first occurred in November 1974. The intense itching sensation was localized to both sides of the trunk, in symmetrical areas corresponding to the thoracic spinal segments seven or eight. The attacks occurred on either side, but most often were right-sided. The itching sometimes affected the back, but was more often localized to the front of the trunk near the midline. Three days before the attacks started the patient noticed decreased sensitivity to light touch within the affected area on the right side. Within the affected areas on both sides the application of cold and pinpricking gave a hyperpathic response. The itching started abruptly but ended more gradually.
Paroxysmal itching in multiple sclerosis
557
Sometimes there was a slight burning sensation at the same time. Attacks could be precipitated by light touch within the affected areas. During the attacks application of ice and firm pressure and pinching ofthe itching skin area gave relief for about a minute. The duration of itching was i-io min, and at most she had 20 attacks a day. During carbamazepine treatment (400-800 mg daily) the attacks were less frequent, shorter, and less intense. Treatment with phenytoin (serum level 52 /^mol/l) seemed less effective. Transcutaneous electrical stimulation had no effect. The sensitivity in the affected areas was normalized within 6 months. Sporadic attacks still recurred, however. In the autumn of 1975 the patient had paroxysmal itching localized to the left side of the neck. The attacks occurred during a bout of diminished sensitivity and patches of hyperaesthesia in the body below the head, weakness of the legs and urgency of micturition. Neurological examination during this bout fur±er disclosed signs indicating disorder ofthe pyramidal tracts and ataxia ofthe right arm. The itching sensation was localized within an area, as large as the palm of a hand, in the left side of the neck. Attacks of itching could be precipitated by light touch. Firm pressure and pinching ofthe itching skin area mitigated the itching sensation. The itching was so intense that it disturbed the patient's sleep. The attacks lasted 15-20 min and recurred every 2-30 min. Within the same area occasional attacks of paroxysmal pain also occurred. There were also sporadic attacks of itching within small areas of the right arm. The paroxysmal itching disappeared after i month, concurrent with considerable improvement of the other symptoms. DISCUSSION
The attacks of itching in these three women with multiple sclerosis have several characteristic features in common: (i) The attacks started and ended abruptly. (2) The attacks recurred frequently, usually several times a day. (3) The duration of the attacks was usually several minutes and in no case less than i min. (4) In two cases the itching was localized to an area with numbness and diminished sensitivity. In these cases the distribution of the itching sensation seemed to be segmental (Case i : cervical segment six; Case 3: thoracic segment seven or eight). (5) Two cases (2 and 3) had attacks of itching which could be precipitated by touch and two cases (i and 3) had paroxysmal itching which was relieved by pinching of the itching skin area. (6) In all cases itching attacks occurred on both sides of the body, in symmetrical areas. (7) Carbamazepine was effective against the paroxysmal itching. (8) All three patients had itching attacks in at least two different sites during two different time periods. (9) Lhermitte's sign was present in all cases. (10) Neurological examination between the bouts revealed only minor abnormalities. Paroxysmal symptoms are not infrequent in MS. Twenty-two of 235 patients with undoubted or suspected MS, treated at the Department of Neurology, Uppsala, during an 8-year period, had paroxysmal symptoms during the course of their disease (Osterman & Westerberg, 1975). The most common types of attacks are paroxysmal dysarthria and ataxia, and tonic seizures. Less common are paroxysmal diplopia, paroxysmal akinesia, paroxysmal numbness and paroxysmal pain. The similarities between the different kinds of paroxysmal phenomena in MS—their brevity, their stereotypical appearance in the individual patient, the frequency, the eliciting factors, the effect of phenytoin and carbamazepine—suggest that the same pathogenic mechanism is operative in the various attacks. The findings in some recent studies support the concept that paroxysmal phenomena in MS are caused by transversely spreading ephaptic activation (i.e. activation via an artificial synapse) of axons within a partially demyelinated lesion in fibre tracts somewhere in the central nervous system (Ekbom, Westerberg & Osterman, 1968; Matthews, 1975; Osterman & Westerberg, 1975). Although there are many similarities between the various paroxysmal phenomena in MS, the duration ofthe different types of attacks tends to vary. Attacks of paroxysmal dysarthria and ataxia and of
558
P.O.Osterman
paroxysmal diplopia typically are brief, lasting for only a few seconds up to half a minute, and tonic seizures commonly last about half a minute. In contrast, the duration of paroxysmal pain (Espir & Millac, 1970; Matthews, 1975; present study. Case 3) and paroxysmal itching is usually several minutes. It is noteworthy that one patient (Case 3) experienced both paroxysmal pain and paroxysmal itching ivithin the same skin area, which indicates that these two types of attacks may be related. It is generally agreed that the peripheral and central nervous pathways subserving the sensation of itching are the same as, or closely follow, those which convey the sense of pain (Sweet, 1959; Chapman, Goodell & Wolff, i960). The patients often compared the paroxysmal itching to an intensely itching midge bite. The itching sensation was localized 'beneath' the skin and it was sometimes associated with a burning or aching sensation. In the peripheral nerves this type ofitching is considered to be mediated by unmyelinated C-fibres (Chapman et al., i960). Torebjork (1974) recorded C-fibre activity with micro-electrodes from intact sensory fascicles in the human peroneal nerve. He found that sensations produced by cutaneous stimuli inducing intense afferent C-fibre activity were described as 'burning, or delayed pain', whereas stimuli eliciting low frequency activity were often experienced as 'itch, or burning itch'. It is therefore possible that irritative lesions in pain-conducting fibre pathways may cause both paroxysmal pain and paroxysmal itching—differences in impulse patterns determining whether the sensation will be one of itch or of pain. The frequent occurrence of itching iittacks in symmetrical areas on both sides of the body suggests that the irritative lesion in these cases may be located in the spinal cord, affecting the decussating spinothalamic nerve fibres. The occurrence of itching with a segmental distribution in two cases also indicates that paroxysmal itching may have a spinal origin. Carbamazepine is generally considered to be the most valuable drug for treatment of paroxysmal phenomena in MS and it was effective in controlling the paroxysmal itching in all three cases. In itch due to various disorders, transcutaneous electrical nerve stimulation has been reported to be effective in many cases (Carlsson et al., 1975). This was only tried in one ofthe three present cases and had no effect on the paroxysmal itching. Finally, it is worthy of mention that none ofthe patients thought of a connexion between the paroxysmal itching and their neurological disease. Two of them had consulted physicians and general practitioners about the attacks. Furthermore, paroxysmal itching may be one of the earliest symptoms of MS. ];t is therefore conceivable that other patients with paroxysmal itching may consult physicians other than neurologists for their attacks of itching. REFERENCES CAIRNS, :R.J. (1972) The skin and the nervous system. In: Textbook of Dermatology (Ed. by A.J.Rook, D.S. Wilkinson and F.J.Ebling), 2nd edn. Vol. 2, p. 1791. Blackwell Scientific Publications, Oxford. CARLSSOM, C.-A., AUGUSTINSSON, L . - E . , LUND, S. & ROUPE, G . (1975) Electrical transcutaneous nerve stimulation
for relief of itch. Experientia, 31, 191. CHAPMAN, L.F., GOODELL, H . & WOLFF, H.G. (i960) Structures and processes involved in the sensation of itch. In: Advances in Biology of Skin. Cutaneous Innervation (Ed. by W.Montagna), Vol. i, p. 161. Pergamon Press, Oxford. BKBOM, K.A., WESTERBERG, C.-E. & OSTERMAN, P.O. (1968) Focal sensory-motor seizures of spinal origin. Laru;et, i, 67.
ESPIR, M . L . E . & MILLAC, P. (1970) Treatment of paroxysmal disorders in multiple sclerosis with carbamazepine (Tegretol). Journal of Neurology, Neurosurgery, and Psychiatry, 33, 528. MCALPINE, D . (1972) Symptoms and signs. In: Multiple Sclerosis. A Reappraisal (Ed. by D.McAlpine, C E . Lumsden and E.D.Acheson), 2nd edn, p. 132. Williams and Wilkins, Baltimore. MATTHEWS, W.B. (1975) Paroxysmal symptoms in multiple sclerosis. Journal of Neurology, Neurosurgery, and Psychiatry, 38, 617. OSTERMAN, P.O. & WESTERBEHG, C.-E. (1975) Paroxysmal attacks in multiple sclerosis. Brain, 98, 189. SWEET, \S7.H. (1959) Pain. In: Handbook of Physiology. Sect. i. Neurophysiology (Ed. by J.Field, H.W.Magoun and V.E.Hall), Vol. i, p. 459. American Physiological Society, Washington D.C. K, H.E. (1974) Afferent C units responding to mechanical, thermal and chemical stimuli in human nonglabrous skin. Acta Physiologica Scandinavica, 92, 374.
