Ana Pardal

Periodic limb movements in syringomyelia and syringobulbia.

Twenty‐six patients with syringomyelia were studied with polysomnography to determine the frequency of periodic limb movements (PLM) and its relationship to the presence of a Chiari anomaly, the severity of corticospinal tract involvement, and localization of the syrinx. Sixteen patients showed PLM in stages I and II of non‐REM sleep and three PLM also while awake. There were no statistically significant differences in overall disability, corticospinal signs, presence of an associated Chiari anomaly, and disease duration between patients with and without PLM, although there was a trend for patients with PLM to have more severe disease. There was preservation of the lumbosacral enlargement of the spinal cord by the syrinx in all patients with PLM. The latency delay between lower and upper limb muscles was suggestive of conduction along propriospinal pathways. Syringomyelia may lead to an abnormal state of spinal hyperexcitability favoring the appearance of PLM. Detailed magnetic resonance image studies of patients with different localizations of the syrinx cavities may help to determine which tracts are involved in the production of PLM.

Misdiagnosis in Fabry Disease

OBJECTIVE To evaluate the most frequent diagnostic errors in patients with Fabry disease and the types of specialists most often consulted before diagnosis. STUDY DESIGN We evaluated 45 consecutive symptomatic patients with Fabry disease confirmed by enzymatic tests in males and genetic studies in females. We interviewed the patients, their mothers, or both regarding symptoms, age at onset, medical consultations, and recommended treatments. RESULTS Neuropathic pain was the most frequent initial complaint, and rheumatic fever was the most common diagnosis. Seven patients were treated with penicillin for many years. Ten patients sought medical consultation because of abdominal pain and were diagnosed with food intoxication or nonspecific pain. Six patients sought consultation because of anhidrosis, considered of unclear cause, and angiokeratomas diagnosed as petechiae. Internists and pediatricians were the most frequently consulted specialists. The correct diagnosis was obtained after a mean of 19.7 years. CONCLUSIONS Pediatricians as well as internists commonly misdiagnose Fabry disease. Neuropathic pain, hypohidrosis, and recurrent abdominal pain in childhood or adolescence should include Fabry disease in the differential diagnosis to facilitate earlier diagnosis and treatment of these patients.

Amyotrophic lateral sclerosis IgG‐treated neuromuscular junctions develop sensitivity to L‐type calcium channel blocker

In order to search for early changes induced by the application of human immunoglobulin G (IgG) on motor nerve terminals, IgG from patients with amyotrophic lateral sclerosis (ALS) and control subjects was injected subcutaneously into the levator auris muscle of mice. A week or a month after the last injection, endplate potentials were recorded. No changes in quantal content of transmitter release were observed. In control and ALS IgG‐treated muscles, neurotransmitter release remained sensitive to P/Q‐type and insensitive to N‐type voltage‐sensitive calcium channel (VSCC) blockers as in untreated muscles. In contrast, IgG from 5 of 8 different ALS patients induced a significant reduction in quantal content of the evoked response after incubation with nitrendipine, indicating that a novel sensitivity to this calcium channel blocker appears in these motor nerve terminals. These results indicate that ALS IgG induces plastic changes at nerve terminals. The expression of transmitter release coupled to L‐type VSCC indicate that ALS IgGs are capable of inducing plastic changes at the nerve terminals that may participate in the process leading to neuronal death.

Multifocal motor neuropathy, type 1 diabetes and asymptomatic Hashimoto's thyroiditis: an unusual association.

Immune mediated mechanisms play a role in some forms of diabetic neuropathies. We studied a 17-year-old man who developed asymmetric weakness and atrophy in both upper arms soon after the diagnosis of type 1 diabetes. Nerve conduction studies demonstrated multifocal motor conduction blocks, and serological investigations revealed subclinical Hashimotos thyroiditis. Therapy with intravenous immunoglobulin and cyclophosphamide led to clinical recovery. This is the first observation of an association between type 1 diabetes, multifocal motor neuropathy and Hashimotos thyroiditis.

Playing harp, another unusual task-specific dystonia†

Herein we report a task‐specific dystonia in a 48‐year‐old woman, with an unusual association between a familial harp‐playing dystonia and essential tremor.

Intraneural perineuriomas: diagnostic value of magnetic resonance neurography: León Cejas et al

Intraneural perineurioma (IP) is an under‐recognized hypertrophic peripheral nerve tumor. It affects young patients involving frequently the sciatic nerve and its branches and presents with a progressive, painless and predominantly motor deficit. Magnetic resonance neurography (MRN) is a useful tool to localize the lesion, evaluate its extension, and discriminate between different etiologies. We reviewed the clinical records of 11 patients with pathologically confirm IP. Eight patients were males with mean age 19 years. Initial complains were unilateral steppage (seven patients), bilateral steppage (one patient), unilateral gastrocnemius wasting (one patient), unilateral thigh atrophy (one patient), and unilateral hand weakness (one patient). Nine patients had mild painless sensory loss. Examinations revealed involvement of sciatic nerve extending into the peroneal nerve (eight patients), posterior tibial nerve (one patient), radial nerve (one patient), and femoral nerve (one patient). MRN revealed enlargement of the affected nerve isointense on T1‐weighted, hyperintense on T2 fat‐saturated images, and with avid enhancement on post‐contrast imaging. In all patients, a nerve biopsy confirmed the diagnosis. MRN allows early and non‐invasive identification of this tumor and is a key tool providing localization and differential diagnosis in patients with slowly progressive focal neuropathies.

Neuro-otological and peripheral nerve involvement in Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disease, with multisystemic glycosphingolipids deposits. Neuro-otological involvement leading to hearing loss and vestibular dysfunctions has been described, but there is limited information about the frequency, site of lesion, or the relationship with peripheral neuropathy. The aim was to evaluate the presence of auditory and vestibular symptoms, and assess neurophysiological involvement of the VIII cranial nerve, correlating these findings with clinical and neurophysiological features of peripheral neuropathy. We studied 36 patients with FD with a complete neurological and neuro-otological evaluation including nerve conduction studies, quantitative sensory testing (to evaluate small fiber by warm and cold threshold detection and cold and heat pain), vestibular evoked myogenic potentials, videonistagmography, audiometry and brainstem auditory evoked potentials. Neuro-otologic symptoms included hearing loss (22.2%), vertigo (27.8%) or both (25%). An involvement of either cochlear or vestibular function was identified in most patients (75%). In 70% of our patients the involvement of both cochlear and vestibular function could not be explained by a neural or vascular mechanism. Small fiber neuropathy was identified in 77.7%. There were no significant associations between neuro-otological and QST abnormalities. Neuro-otologic involvement is frequent and most likely under-recognized in patients with FD. It lacks a specific neural or vascular pattern, suggesting multi-systemic, end organ damage. Small fiber neuropathy is an earlier manifestation of FD, but there is no correlation between the development of neuropathy and neuro-otological abnormalities.

Brain MRI findings in children and adolescents with Fabry disease

OBJECTIVE To evaluate the presence of white matter and hemorrhagic lesions in brain MRI of children and adolescents with Fabry disease (FD). METHODS Brain MRI studies in 44 consecutive children and teenagers (20 boys, mean age 14.6 years, range 7-21 years) were evaluated using classic sequences as well as, GRE-weighted images, for white matter lesions (WML) and chronic microbleed detection. All patients lacked history of stroke or TIA. Brain MRI findings in 46 consecutive children and adolescents without FD, referred for the evaluation of headaches (36 females, mean age 14.1 years, range 7-21 years) were evaluated as a control group. Additionally, we assessed the clinical manifestations of FD. RESULTS Seven children (15.9%) with FD had brain MRI evidence of asymptomatic WML (5 girls, mean age 14.8 years, range: 13-20 years) compared with 3 children (6.5%) in the control group (p = 0.01). Brain abnormalities in patients with FD revealed WML, deep gray matter and infratentorial involvement. Three patients presented two lesions each. None of the children showed microbleeds. Regarding clinical manifestations, 90.9% of the patients had signs or symptoms of FD. CONCLUSION We identified asymptomatic white matter brain lesions in 15.9% of children with FD without clinical history of stroke. FD is a treatable disorder that should be routinely included in the differential diagnosis of both symptomatic and asymptomatic brain lesions in children and adolescents. The detection of brain lesions may foster earlier treatment.

S47. Sensory Guillain Barré syndrome

Introduction The classic Guillain Barre syndrome (GBS) is characterized by motor weakness, hyporreflexia, but limited sensory deficits. Sensory variants involving either small or large fibers or both are unusual and represent a diagnostic challenge. Methods We described 6 patients presenting with the sensory variant of GBS and retrospectively analyzed the clinical and electrophysiological findings of patients fulfilling the criteria for Sensory GBS according to Oh et al. criteria. Results Six patients were identified (mean age 38 years: range 15–54 years). Four had a previous infection. They all consulted due to distal painful paresthesias and allodynia. On examination the 6 patients presented normal strength and normal cranial nerves through the course of the disease with reduced knee and ankle reflexes in 3 patients. Distal hyperesthesia to pinprick was identified in 3 and one of them additionally had hyperhidrosis and constipation. Two additional patients presented hypoesthesia to pinprick and temperature. One patient had distal proprioceptive sensory loss with sensory ataxia. CSF albumin cytological dissociation was present in 3 patients. Nerve conduction studies (NCS) identified a sensory motor demyelinating neuropathy in 2 patients. Among the 4 with normal NCS, 2 had abnormal cold and warm threshold in their QST evaluation. All patients received symptomatic treatment for the neuropathic pain and only two IvIg therapies. Longstanding pain, fatigue or both were persistent findings in 5 patients after a mean follow up of 6 months. Conclusion The sensory variant of GBS is both an infrequent presentation and a diagnostic challenge. Longstanding pain and fatigue are common persisting findings.

130. Evaluation of peripheral neuropathy in Fabry disease

The spatiotemporal discontinuity of the visual input such as when conspecifics suddenly disappear behind a wall is a common occurrence for human beings. Our hypothesis is that an implicit motor simulation mechanism would be triggered during the complete occlusion of biological motion. Event-related potentials were recorded from ten healthy subjects during the visual presentation of point-light displays depicting a walking person (Biological Motion: BM).Control condition consisted in displays of scrambled motion (SM). Both stimuli disappeared behind an obstacle 1.6s after the beginning of the video and reappeared 2.3s after their first disappearance. A total of 100 point-light animations was presented in a color flat screen. ERP amplitude was collected from all electrodes and aligned with respect either to the stimuli appearance or occlusion. ANOVA with repeated measures was performed for T5, T6, P3 and P4 electrodes. Data analysis showed a pronounced negativity for BM versus SM after the point-light stimulus onset in the right parietotemporal region corresponding to T6 and P4. Moreover, during the occlusion phase, cortical activity in this parietotemporal site remained greater for BM than for SM. The main result suggests the involvement of STS-Parietal complex during the occlusion phase of biological motion, indicating that these cortical areas play a role in the human capacity of biological motion permanence.