Journal of the Neurological Sciences 352 (2015) 135–136
Contents lists available at ScienceDirect
Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns
Letter to the Editor Bilateral medial medullary infarction presenting as Guillain Barré Syndrome: A diagnostic challenge Keywords: Medial medullary infarction GBS DWI-negative stroke
1. Introduction Medial medullary infarction (MMI) is an uncommon entity (0.5–1.5% of all strokes), and bilateral MMI is extremely rare [1,2]. Although quadriparesis, loss of deep sensation and hypoglossal palsy have been described as the classical picture for bilateral MMI, the clinical presentation is variable and non-specific, usually delaying diagnosis [2]. Moreover, initial diffusion weighted imaging (DWI) is often negative [3]. Bilateral MMI can be misdiagnosed as Guillain Barré Syndrome (GBS), since patients present with sudden onset of quadriparesis, sensory disturbances, bulbar dysfunction and progression to respiratory failure [2,4]. We present a case of DWI-negative bilateral MMI, initially thought to be GBS. 2. Case presentation An 81-year old man with history of peripheral neuropathy and vitamin B12 deficiency presented to the emergency department with dysarthria, right facial numbness and generalized weakness. Physical exam revealed hypertension, left palate weakness, mild left facial palsy, tongue midline, normal strength in all extremities and severely reduced vibration sense with moderately preserved proprioception. Transthoracic echocardiogram and computed tomography (CT) of the head were unremarkable. CT angiography of the head and neck showed multiple areas of atherosclerosis, most notably a hypoplastic right vertebral artery and moderate stenosis of the left vertebral artery at the vertebrobasilar junction. Magnetic resonance imaging (MRI) of the brain was performed 10 h from the onset of symptoms and was negative for acute stroke (Fig. 1A). Symptoms improved and the patient was discharged with a diagnosis of severe progressive peripheral neuropathy. The following day, the patient had significant gait instability, progressively worsening weakness and nausea. Examination showed dysarthria, 3/5 strength in all extremities, increased tone in all extremities and decreased sensation in all extremities and trunk. The patient had normal deep tendon reflexes. Given the recent admission and negative test results for stroke, blood and urine were tested for infections and toxins, yielding no abnormality. The patient progressed towards respiratory failure within 72 h and was transferred to the intensive care unit and intubated. At this point the patient was thought to have GBS. Subsequently, electromyogram/nerve conduction studies
http://dx.doi.org/10.1016/j.jns.2015.03.048 0022-510X/© 2015 Elsevier B.V. All rights reserved.
(EMG/NCS) suggested a central, rather than a peripheral process with normal F-waves, no evidence of active demyelination and no evidence of neuromuscular junction disorder. Lumbar puncture revealed protein at 63 mg/dL, glucose at 79 mg/dL, total white blood cells 1/mm3 and red blood cells 5/mm3. Cerebrospinal fluid culture (CSF) was negative. Repeat MRI of the brain with and without gadolinium showed the presence of bilateral medullary pyramidal ischemia and central medullary ischemia (heart shaped appearance) with no evidence of enhancement (Fig. 1B). The patient was diagnosed with bilateral MMI. He was assessed by the palliative care team and was discharged to hospice care where he subsequently died due to respiratory failure.
3. Discussion Bilateral MMI is extremely rare [1,2,4–6]. The traditional presentation of bilateral MMI consists of acute progressive tetraplegia associated with tongue weakness, sensory disturbance of all four limbs and posterior column sensation loss [6]. However, this description may be less common than expected. A recent systematic review showed that the most common clinical presentations for bilateral MMI consisted of bilateral motor weakness (64.9%), dysarthria (48.6%), nystagmus (48.6%), sensory abnormalities (43.2%), hypoglossal palsy (40.5%), and dysphagia (16.2%) [2]. It is worth noting that our patient did not present with lingual paresis. Unlike what we would predict, hypoglossal palsy is seen in less than half of patients with bilateral MMI. This observation can be explained by the anatomical orientation of the hypoglossal fibers, which run lateral to the medial lemniscus and pyramid. These fibers can occasionally be spared in cases of medial medullary infarct [7,8]. GBS is one of the most common misdiagnoses because of its higher prevalence and the similitude of the clinical picture [4]. GBS can initially present with bilateral sensory and/or motor symptoms, which progress to symmetrical bilateral limb weakness, similar to our patient [9]. Respiratory failure occurs in about 25% of GBS cases [2,9]. The cytoalbuminological dissociation in CSF may not be present in the first week of the illness, which can cause confusion between GBS and MMI. Nerve conduction studies can clarify the diagnosis by identifying the GBS subtype and help to exclude other disorders [4]. Notably, two thirds of GBS cases are preceded by symptoms of upper respiratory tract infection or diarrhea [9], which our patient did not present. Our patient also had normal deep tendon reflexes, which is inconsistent with classic GBS, but was misdiagnosed due to the ascending weakness pattern and the initial negative MRI. MMI can be caused by thrombosis of the vertebral artery, vertebral artery perforator occlusion and anterior spinal artery occlusion [1,6]. The most likely etiology of bilateral MMI is thrombosis of larger vessels, while other proposed mechanisms include small vessel disease and embolic or vertebral dissection [2,10]. MRI can show the characteristic heart appearance on DWI [10]. However, bilateral MMI may present initially with negative MRI findings as seen in our patient. In a recent case series 2.3% of ischemic strokes subjected to MRI were
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Fig. 1. A) Initial MRI, DWI-negative for acute stroke. B) Repeat brain MRI, DWI shows classic “heart appearance” sign, characteristic of medial medullary infarct.
DWI-negative [3]. The most commonly DWI-negative stroke syndromes are the posterior circulation and lacunar strokes. In fact DWI-negative infarcts occur twice as often in the posterior circulation as in the anterior circulation. This can be due to an artifact produced by the local field effect, distorting the image and preventing identification of ischemia [3]. 4. Conclusion Our patient had progressive bilateral MMI. The subacute presentation and the initial negative MRI made the diagnosis difficult, with the clinical picture mimicking GBS. This case highlights the importance of high clinical suspicion of bilateral MMI in patients with symmetric weakness, dysarthria and progression to respiratory failure. We suggest taking into consideration history of recent infection and especially the presence of significant vascular risk factors when making a diagnosis. Patients must undergo thorough physical examination, in particular assessing deep tendon reflexes and recognizing that lingual paresis is frequently absent in bilateral MMI. We would also like to emphasize the importance of EMG studies and to highlight that posterior circulation infarcts may be initially DWI-negative, and therefore repeat MRI might be needed in cases of high clinical suspicion. Conflict of interest
[4] Ma L, Deng Y, Wang J, Du F, Xia F, Liu Y, et al. Bilateral medial medullary infarction presenting as Guillain–Barré-like syndrome. Clin Neurol Neurosurg 2011;113:589–91. [5] Kleinert G, Fazekas F, Kleinert R, Schmidt R, Payers F, Offenbacher H, et al. Bilateral medial medullary infarction: magnetic resonance imaging and correlative histopathologic findings. Eur Neurol 1993;33:74–6. [6] Maeda M, Shimono T, Tsukahara H, Maier SE, Takeda K. Acute bilateral medial medullary infarction: a unique ‘heart appearance’ sign by diffusion-weighted imaging. Eur Neurol 2004;51:236–7. [7] Brazis PW, Masdeu JC, Biller J. Localization in clinical neurology. Lippincott Williams & Wilkins; 2012. [8] Kim JS, Kim HG, Chung CS. Medial medullary syndrome report of 18 new patients and a review of the literature. Stroke 1995;26:1548–52. [9] Yuki N, Hartung H-P. Guillain–Barré syndrome. N Engl J Med 2012;366:2294–304. [10] Tai M-LS, Katiman E, Rahmat K, Tan CT. Acute bilateral medial medullary infarct with hypoplastic vertebral artery. Clin Neurol Neurosurg 2012;114: 1365–7 [Tai, 2012 #38].
Mayra Montalvo Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, 96/79 13th Street, Boston, MA 02129, USA E-mail address: [email protected]. Corresponding author at: Neuromodulation center 96/79 13th St, Boston, MA 02129, USA. Rushna Ali Department of Neurosurgery, Henry Ford Health System, 2799 W. Grand Blvd, Detroit, MI 48202, USA E-mail address: [email protected].
There is no conflict of interest. References [1] Krishnan M, Rajan P, Kesavadas C, Iyer RS. The ‘heart appearance’ sign in MRI in bilateral medial medullary infarction. Postgrad Med J 2011;87:156–7. [2] Pongmoragot J, Parthasarathy S, Selchen D, Saposnik G. Bilateral medial medullary infarction: a systematic review. J Stroke Cerebrovasc Dis 2013;22: 775–80. [3] Watts J, Wood B, Kelly A, Alvaro A. Stroke syndromes associated with DWI-negative MRI include ataxic hemiparesis and isolated internuclear ophthalmoplegia. Neurology 2013;3:186–91.
Muhib Khan Department of Neurology, Warren Alpert Medical School of Brown University, 110 Lockwood Street, Suite 324, Providence, RI 02903, USA E-mail address: [email protected]. 20 February 2015
Contents lists available at ScienceDirect
Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns
Letter to the Editor Bilateral medial medullary infarction presenting as Guillain Barré Syndrome: A diagnostic challenge Keywords: Medial medullary infarction GBS DWI-negative stroke
1. Introduction Medial medullary infarction (MMI) is an uncommon entity (0.5–1.5% of all strokes), and bilateral MMI is extremely rare [1,2]. Although quadriparesis, loss of deep sensation and hypoglossal palsy have been described as the classical picture for bilateral MMI, the clinical presentation is variable and non-specific, usually delaying diagnosis [2]. Moreover, initial diffusion weighted imaging (DWI) is often negative [3]. Bilateral MMI can be misdiagnosed as Guillain Barré Syndrome (GBS), since patients present with sudden onset of quadriparesis, sensory disturbances, bulbar dysfunction and progression to respiratory failure [2,4]. We present a case of DWI-negative bilateral MMI, initially thought to be GBS. 2. Case presentation An 81-year old man with history of peripheral neuropathy and vitamin B12 deficiency presented to the emergency department with dysarthria, right facial numbness and generalized weakness. Physical exam revealed hypertension, left palate weakness, mild left facial palsy, tongue midline, normal strength in all extremities and severely reduced vibration sense with moderately preserved proprioception. Transthoracic echocardiogram and computed tomography (CT) of the head were unremarkable. CT angiography of the head and neck showed multiple areas of atherosclerosis, most notably a hypoplastic right vertebral artery and moderate stenosis of the left vertebral artery at the vertebrobasilar junction. Magnetic resonance imaging (MRI) of the brain was performed 10 h from the onset of symptoms and was negative for acute stroke (Fig. 1A). Symptoms improved and the patient was discharged with a diagnosis of severe progressive peripheral neuropathy. The following day, the patient had significant gait instability, progressively worsening weakness and nausea. Examination showed dysarthria, 3/5 strength in all extremities, increased tone in all extremities and decreased sensation in all extremities and trunk. The patient had normal deep tendon reflexes. Given the recent admission and negative test results for stroke, blood and urine were tested for infections and toxins, yielding no abnormality. The patient progressed towards respiratory failure within 72 h and was transferred to the intensive care unit and intubated. At this point the patient was thought to have GBS. Subsequently, electromyogram/nerve conduction studies
http://dx.doi.org/10.1016/j.jns.2015.03.048 0022-510X/© 2015 Elsevier B.V. All rights reserved.
(EMG/NCS) suggested a central, rather than a peripheral process with normal F-waves, no evidence of active demyelination and no evidence of neuromuscular junction disorder. Lumbar puncture revealed protein at 63 mg/dL, glucose at 79 mg/dL, total white blood cells 1/mm3 and red blood cells 5/mm3. Cerebrospinal fluid culture (CSF) was negative. Repeat MRI of the brain with and without gadolinium showed the presence of bilateral medullary pyramidal ischemia and central medullary ischemia (heart shaped appearance) with no evidence of enhancement (Fig. 1B). The patient was diagnosed with bilateral MMI. He was assessed by the palliative care team and was discharged to hospice care where he subsequently died due to respiratory failure.
3. Discussion Bilateral MMI is extremely rare [1,2,4–6]. The traditional presentation of bilateral MMI consists of acute progressive tetraplegia associated with tongue weakness, sensory disturbance of all four limbs and posterior column sensation loss [6]. However, this description may be less common than expected. A recent systematic review showed that the most common clinical presentations for bilateral MMI consisted of bilateral motor weakness (64.9%), dysarthria (48.6%), nystagmus (48.6%), sensory abnormalities (43.2%), hypoglossal palsy (40.5%), and dysphagia (16.2%) [2]. It is worth noting that our patient did not present with lingual paresis. Unlike what we would predict, hypoglossal palsy is seen in less than half of patients with bilateral MMI. This observation can be explained by the anatomical orientation of the hypoglossal fibers, which run lateral to the medial lemniscus and pyramid. These fibers can occasionally be spared in cases of medial medullary infarct [7,8]. GBS is one of the most common misdiagnoses because of its higher prevalence and the similitude of the clinical picture [4]. GBS can initially present with bilateral sensory and/or motor symptoms, which progress to symmetrical bilateral limb weakness, similar to our patient [9]. Respiratory failure occurs in about 25% of GBS cases [2,9]. The cytoalbuminological dissociation in CSF may not be present in the first week of the illness, which can cause confusion between GBS and MMI. Nerve conduction studies can clarify the diagnosis by identifying the GBS subtype and help to exclude other disorders [4]. Notably, two thirds of GBS cases are preceded by symptoms of upper respiratory tract infection or diarrhea [9], which our patient did not present. Our patient also had normal deep tendon reflexes, which is inconsistent with classic GBS, but was misdiagnosed due to the ascending weakness pattern and the initial negative MRI. MMI can be caused by thrombosis of the vertebral artery, vertebral artery perforator occlusion and anterior spinal artery occlusion [1,6]. The most likely etiology of bilateral MMI is thrombosis of larger vessels, while other proposed mechanisms include small vessel disease and embolic or vertebral dissection [2,10]. MRI can show the characteristic heart appearance on DWI [10]. However, bilateral MMI may present initially with negative MRI findings as seen in our patient. In a recent case series 2.3% of ischemic strokes subjected to MRI were
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Letter to the Editor
Fig. 1. A) Initial MRI, DWI-negative for acute stroke. B) Repeat brain MRI, DWI shows classic “heart appearance” sign, characteristic of medial medullary infarct.
DWI-negative [3]. The most commonly DWI-negative stroke syndromes are the posterior circulation and lacunar strokes. In fact DWI-negative infarcts occur twice as often in the posterior circulation as in the anterior circulation. This can be due to an artifact produced by the local field effect, distorting the image and preventing identification of ischemia [3]. 4. Conclusion Our patient had progressive bilateral MMI. The subacute presentation and the initial negative MRI made the diagnosis difficult, with the clinical picture mimicking GBS. This case highlights the importance of high clinical suspicion of bilateral MMI in patients with symmetric weakness, dysarthria and progression to respiratory failure. We suggest taking into consideration history of recent infection and especially the presence of significant vascular risk factors when making a diagnosis. Patients must undergo thorough physical examination, in particular assessing deep tendon reflexes and recognizing that lingual paresis is frequently absent in bilateral MMI. We would also like to emphasize the importance of EMG studies and to highlight that posterior circulation infarcts may be initially DWI-negative, and therefore repeat MRI might be needed in cases of high clinical suspicion. Conflict of interest
[4] Ma L, Deng Y, Wang J, Du F, Xia F, Liu Y, et al. Bilateral medial medullary infarction presenting as Guillain–Barré-like syndrome. Clin Neurol Neurosurg 2011;113:589–91. [5] Kleinert G, Fazekas F, Kleinert R, Schmidt R, Payers F, Offenbacher H, et al. Bilateral medial medullary infarction: magnetic resonance imaging and correlative histopathologic findings. Eur Neurol 1993;33:74–6. [6] Maeda M, Shimono T, Tsukahara H, Maier SE, Takeda K. Acute bilateral medial medullary infarction: a unique ‘heart appearance’ sign by diffusion-weighted imaging. Eur Neurol 2004;51:236–7. [7] Brazis PW, Masdeu JC, Biller J. Localization in clinical neurology. Lippincott Williams & Wilkins; 2012. [8] Kim JS, Kim HG, Chung CS. Medial medullary syndrome report of 18 new patients and a review of the literature. Stroke 1995;26:1548–52. [9] Yuki N, Hartung H-P. Guillain–Barré syndrome. N Engl J Med 2012;366:2294–304. [10] Tai M-LS, Katiman E, Rahmat K, Tan CT. Acute bilateral medial medullary infarct with hypoplastic vertebral artery. Clin Neurol Neurosurg 2012;114: 1365–7 [Tai, 2012 #38].
Mayra Montalvo Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, 96/79 13th Street, Boston, MA 02129, USA E-mail address: [email protected]. Corresponding author at: Neuromodulation center 96/79 13th St, Boston, MA 02129, USA. Rushna Ali Department of Neurosurgery, Henry Ford Health System, 2799 W. Grand Blvd, Detroit, MI 48202, USA E-mail address: [email protected].
There is no conflict of interest. References [1] Krishnan M, Rajan P, Kesavadas C, Iyer RS. The ‘heart appearance’ sign in MRI in bilateral medial medullary infarction. Postgrad Med J 2011;87:156–7. [2] Pongmoragot J, Parthasarathy S, Selchen D, Saposnik G. Bilateral medial medullary infarction: a systematic review. J Stroke Cerebrovasc Dis 2013;22: 775–80. [3] Watts J, Wood B, Kelly A, Alvaro A. Stroke syndromes associated with DWI-negative MRI include ataxic hemiparesis and isolated internuclear ophthalmoplegia. Neurology 2013;3:186–91.
Muhib Khan Department of Neurology, Warren Alpert Medical School of Brown University, 110 Lockwood Street, Suite 324, Providence, RI 02903, USA E-mail address: [email protected]. 20 February 2015
