Br. vet.
7. (1990) . 146, 8 8
SHORT COMMUNICATION
CEREBROSPINAL FLUID STUDIES IN NORMAL COWS AND CASES OF BOVINE SPONGIFORM ENCEPHALOPATHY
P . R. SCOTT*, B . M . ALDRIDGE*, M . CLARKEt and R. G . WILLt *Large Animal Practice, Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Veterinary Field Station, Easter Bush, Roslin, Midlothian EH25 9RG; (Area Clinical Neurophysiology Service, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU
INTRODUCTION Cerebrospinal fluid (CSF) samples were analysed from 20 cases of bovine spongiform encephalopathy (BSE) and from 10 similarly aged normal cows . The blood-brain barrier (BBB) appeared to be undamaged and there was no evidence of intrathecal immunoglobulin (Ig) production in BSE cases compared with controls . The absence of any gross immunological response may allow this recently identified spongiform encephalopathy to be differentiated from bacterial and viral infections of the central nervous system which damage the BBB or result in intrathecal Ig production .
MATERIALS AND METHODS Cerebrospinal fluid samples were collected from the lumbosacral (L-S) site under local anaesthesia in the standing animal restrained in a cattle crush. A midline approach midway between the last palpable lumbar vertebral dorsal spine (L 5) and the first palpable sacral dorsal spine (S2) was chosen . A 5 cm 14 gauge needle was used to penetrate the skin, connective tissue and interspinous ligament . This track was followed by a 10 cm 18 gauge spinal needle with stylet . Increased resistance to the direction of the needle could be appreciated at a depth of 6-8 cm when the interarcuate ligament was penetrated . Following removal of the stylet CSF appeared at the needle hub except for approximately 25% of cases where gentle syringe aspiration was required to obtain CSF . Between 25 and 60 ml of CSF could be collected . At the same time a blood sample was obtained by venepuncture . Total CSF white blood cell (WBC) counts were made using a standard haemocytometer. After collection on to a glass microscope slide, cells were stained with Leishman stain and differential WBC counts were made . Serum albumin concentration was determined by bromocrescol green dye binding technique . Protein fractionation was determined by agarose gel electrophoresis . RESULTS The results are presented in Table I .
89
CSF FLUID IN NORMAL AND BSE COWS
There was no significant difference between normal cows and those with BSE for any of the CSF variables measured . The large standard deviation recorded for the albumin quota was a result of the variation in total CSF albumin as the serum albumin concentration was relatively constant. Specific gravity estimations and cytology values were not measured in the normal cows and therefore reference values have been quoted . In the BSE cows the differential white blood cell count was based on 5-20 cells . Table I Cerebrospinal fluid analysis in 20 cows with BSE and 10 normal similarly aged cows BSE Variable
Specific gravity Total WBCs (X 10 6/1) Cytology Lymphocytes (%) Neutrophils (%) Histocytes (%) Total protein (g/1) Total albumin (g/1) Albumin quota Albumin % Globulin (%) Alpha-1 Alpha-2 Beta-1 / Beta-2 Gamma
Mean
Normal SD
1 . 006 < 12 . 5
0-0008
Mean
SD
< 1 . 010 < 5.0
45 30 25 0 . 37 0 . 16 0-0045 44-2
> 95 < 5 0 . 13 0 . 05 0-0022 5.7
0-43 0 . 18 0 . 0033 37-8
0 . 19 0 . 09 0 . 0016 6-0
13 . 3 11 . 2
3-2 2-8
16-7 15-1
4. 1 5-0
21 . 0 9-6
2-2 2-8
20-2 9-8
2-2 4-3
DISCUSSION The maintenance of the blood-brain barrier in BSE cases is indicated by the normal values for CSF albumin percentage and albumin quota when compared to control cows . The significance of an elevated CSF albumin percentage and albumin quota in a small number of control and BSE cows could not be determined . These elevated values were caused by an increase in the CSF total protein concentration and a corresponding increase in the albumin concentration . The normal CSF Ig percentage in BSE cases indicated a lack of intrathecal Ig production . In addition there was no change in the relative amounts of immunoglobulin, in particular the gammaglobulin fraction . The lack of immune response within the central nervous system (CNS) in BSE cases reported in this series is in agreement with the histopathology which showed no evidence of cellular infiltration of the CNS (Wells et al., 1987). Similarly, no cellular or protein changes in CSF have been reported in human patients affected with the spongiform encephalopathic condition Creutzfeldt Jakob disease (CJD) (Will & Matthews, 1984) .
90
BRITISH VETERINARY JOURNAL, 146, 1
This study which reports no departure from normal in CSF cytology, protein concentration and electrophoretic pattern, will allow the differentiation of BSE from certain viral and bacterial infections of the CNS which evoke an inflammatory response (Binkhorst, 1982) . This in turn may assist veterinarians in the diagnosis of BSE when combined with a thorough investigation of the animal's history, clinical presentation and detailed neurological examination (Aldridge et al., 1988) .
REFERENCES ALDRIDGE, B . M ., Scorr, P . R ., CLARKE, M ., MCINNES, A. & WILL, R. G . (1988) . In Proceedings. XVth World Butatrics Congress, Palma de Mallorca, Spain, 1531-1534. BINKHORST, G . J . (1982) . In Proceedings. XIIth World Congress on Diseases of Cattle, the Netherlands. Volume II, 864, Utrecht, Netherlands . WELLS, G. A . H ., SCOTT, A . C ., JOHNSON, C . T ., GUNNING, R . F., HANCOCK, R . D., JEFFREY, M ., DAWSON, M . & BRADLEY, R . (1987). Veterinary Record 121, 419 . WILL, R. G . & MATFHEWS, W . B . (1984). Journal ofNeurology, Neurosurgery (Accepted for publication 18 September 1989)
and Psychiatry 47,134 .
7. (1990) . 146, 8 8
SHORT COMMUNICATION
CEREBROSPINAL FLUID STUDIES IN NORMAL COWS AND CASES OF BOVINE SPONGIFORM ENCEPHALOPATHY
P . R. SCOTT*, B . M . ALDRIDGE*, M . CLARKEt and R. G . WILLt *Large Animal Practice, Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Veterinary Field Station, Easter Bush, Roslin, Midlothian EH25 9RG; (Area Clinical Neurophysiology Service, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU
INTRODUCTION Cerebrospinal fluid (CSF) samples were analysed from 20 cases of bovine spongiform encephalopathy (BSE) and from 10 similarly aged normal cows . The blood-brain barrier (BBB) appeared to be undamaged and there was no evidence of intrathecal immunoglobulin (Ig) production in BSE cases compared with controls . The absence of any gross immunological response may allow this recently identified spongiform encephalopathy to be differentiated from bacterial and viral infections of the central nervous system which damage the BBB or result in intrathecal Ig production .
MATERIALS AND METHODS Cerebrospinal fluid samples were collected from the lumbosacral (L-S) site under local anaesthesia in the standing animal restrained in a cattle crush. A midline approach midway between the last palpable lumbar vertebral dorsal spine (L 5) and the first palpable sacral dorsal spine (S2) was chosen . A 5 cm 14 gauge needle was used to penetrate the skin, connective tissue and interspinous ligament . This track was followed by a 10 cm 18 gauge spinal needle with stylet . Increased resistance to the direction of the needle could be appreciated at a depth of 6-8 cm when the interarcuate ligament was penetrated . Following removal of the stylet CSF appeared at the needle hub except for approximately 25% of cases where gentle syringe aspiration was required to obtain CSF . Between 25 and 60 ml of CSF could be collected . At the same time a blood sample was obtained by venepuncture . Total CSF white blood cell (WBC) counts were made using a standard haemocytometer. After collection on to a glass microscope slide, cells were stained with Leishman stain and differential WBC counts were made . Serum albumin concentration was determined by bromocrescol green dye binding technique . Protein fractionation was determined by agarose gel electrophoresis . RESULTS The results are presented in Table I .
89
CSF FLUID IN NORMAL AND BSE COWS
There was no significant difference between normal cows and those with BSE for any of the CSF variables measured . The large standard deviation recorded for the albumin quota was a result of the variation in total CSF albumin as the serum albumin concentration was relatively constant. Specific gravity estimations and cytology values were not measured in the normal cows and therefore reference values have been quoted . In the BSE cows the differential white blood cell count was based on 5-20 cells . Table I Cerebrospinal fluid analysis in 20 cows with BSE and 10 normal similarly aged cows BSE Variable
Specific gravity Total WBCs (X 10 6/1) Cytology Lymphocytes (%) Neutrophils (%) Histocytes (%) Total protein (g/1) Total albumin (g/1) Albumin quota Albumin % Globulin (%) Alpha-1 Alpha-2 Beta-1 / Beta-2 Gamma
Mean
Normal SD
1 . 006 < 12 . 5
0-0008
Mean
SD
< 1 . 010 < 5.0
45 30 25 0 . 37 0 . 16 0-0045 44-2
> 95 < 5 0 . 13 0 . 05 0-0022 5.7
0-43 0 . 18 0 . 0033 37-8
0 . 19 0 . 09 0 . 0016 6-0
13 . 3 11 . 2
3-2 2-8
16-7 15-1
4. 1 5-0
21 . 0 9-6
2-2 2-8
20-2 9-8
2-2 4-3
DISCUSSION The maintenance of the blood-brain barrier in BSE cases is indicated by the normal values for CSF albumin percentage and albumin quota when compared to control cows . The significance of an elevated CSF albumin percentage and albumin quota in a small number of control and BSE cows could not be determined . These elevated values were caused by an increase in the CSF total protein concentration and a corresponding increase in the albumin concentration . The normal CSF Ig percentage in BSE cases indicated a lack of intrathecal Ig production . In addition there was no change in the relative amounts of immunoglobulin, in particular the gammaglobulin fraction . The lack of immune response within the central nervous system (CNS) in BSE cases reported in this series is in agreement with the histopathology which showed no evidence of cellular infiltration of the CNS (Wells et al., 1987). Similarly, no cellular or protein changes in CSF have been reported in human patients affected with the spongiform encephalopathic condition Creutzfeldt Jakob disease (CJD) (Will & Matthews, 1984) .
90
BRITISH VETERINARY JOURNAL, 146, 1
This study which reports no departure from normal in CSF cytology, protein concentration and electrophoretic pattern, will allow the differentiation of BSE from certain viral and bacterial infections of the CNS which evoke an inflammatory response (Binkhorst, 1982) . This in turn may assist veterinarians in the diagnosis of BSE when combined with a thorough investigation of the animal's history, clinical presentation and detailed neurological examination (Aldridge et al., 1988) .
REFERENCES ALDRIDGE, B . M ., Scorr, P . R ., CLARKE, M ., MCINNES, A. & WILL, R. G . (1988) . In Proceedings. XVth World Butatrics Congress, Palma de Mallorca, Spain, 1531-1534. BINKHORST, G . J . (1982) . In Proceedings. XIIth World Congress on Diseases of Cattle, the Netherlands. Volume II, 864, Utrecht, Netherlands . WELLS, G. A . H ., SCOTT, A . C ., JOHNSON, C . T ., GUNNING, R . F., HANCOCK, R . D., JEFFREY, M ., DAWSON, M . & BRADLEY, R . (1987). Veterinary Record 121, 419 . WILL, R. G . & MATFHEWS, W . B . (1984). Journal ofNeurology, Neurosurgery (Accepted for publication 18 September 1989)
and Psychiatry 47,134 .
