96. Blink reflex intraoperative monitoring during microvascular decompression for hemifacial spasm: Our experience

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Society Proceedings / Clinical Neurophysiology 126 (2015) e1–e28

Serum was positive for anti-disialosyl IgM antibodies and cold agglutinins. NCS/EMG showed a mild chronic sensory-motor neuropathy. Cortical somatosensory evoked potentials by tibial nerve stimulation at the ankle were deranged, whereas responses at the popliteal fossa and sural NCS were largely preserved. This suggests a proximal alteration of peripheral sensory conduction. These data further confirm the heterogeneous presentation of CANOMAD.

The most useful electrodiagnostic criteria are DGBSG. For early diagnosis, however, the standard criteria are not sensitive while the new ones are not specific. Therefore, diagnosis of GBS remains in first instance based on clinical examination. ENG should be performed only in patients meeting clinical criteria to increase level of diagnostic certainty. doi:10.1016/j.clinph.2014.10.114

doi:10.1016/j.clinph.2014.10.112

94. Chronic pure motor axonal plexopathy responsive to immunomodulatory treatment: Clinical, electrophysiological and magnetic resonance imaging correlations—F. Donato, A. Morini, S. Zimatore, S. Romito, L. Alessandrini, G. Moretto, G. Squintani (Verona, Italy, Trento, Italy) A 70 year old woman with a diagnosis of left radial nerve entrapment at the arcade of Frohse, unsuccessfully surgically treated, came to our attention for a progressive weakness in her left arm that began 6 years before. Neurological examination showed severe hypotrophic muscles innervated by left ulnar and radial nerves and reduced strength at the level of forearm flexors, arm and shoulder muscles. No sensory deficits were reported. Serum antiganglioside antibody research and cerebrospinal fluid analysis was negative. EMG testing revealed neurogenic MUPs and poor recruitment in left forearm, arm and shoulder muscles and low cMAP amplitude stimulating the left radial and ulnar nerve associated to active denervation. No sensory impairment or conduction blocks detected with proximal stimulation and collision techniques were present. MRI disclosed hyperintensity on T2-weighted STIR sequences of the left brachial plexus, compatible with hypertrophic neuropathy. The patient was treated with ivIg with clinical benefit. The MRI and electrophysiological picture in our patient, together with response to ivIg, were consistent with a diffuse inflammatory process affecting the brachial plexus, with very likely axonal pathophysiology. Disimmune axonopathies should be recognised because are treatable disorders: MRI in selected cases, may be considered in the diagnostic work-up of disimmune neuropathy/plexopathy. doi:10.1016/j.clinph.2014.10.113

95. Guillain–Barre syndrome: Comparison of neurophysiological standards parameters and validation of criteria for the diagnosis at an early stage—M. Scarpino, R. Carrai, S. Canden, C. Cossu, A. Amantini, A. Grippo (Firenze, Italy) Electrodiagnostic criteria are of support to the diagnosis of GBS. Ho/Hadden (HH) criteria are the ones most commonly used although little specific. Dutch GBS Study Group (DGBSG) criteria seem to be the most sensitive and specific. Both, however, are not sensitive for early diagnosis of GBS. The aim of our study is to determine the more useful criteria in clinical practice and the utility of the proposed criteria for early diagnosis. Prospective study of patients admitted to AOU-Careggi with clinical suspicion of GBS. Clinical evaluation was based on Asbury criteria. Neurophysiological examination included standard nerves conduction, H-reflex, A-wave and distal CMAP duration. We recruited 20 patients, 1/3 met clinical criteria. HH criteria were positive in 4 patients, one of which had a diabetic polyneuropathy. DGBSG criteria were positive only in patients affected by GBS/CIDP. All the proposed criteria for early diagnosis resulted not specific for GBS.

96. Blink reflex intraoperative monitoring during microvascular decompression for hemifacial spasm: Our experience—V. Simioni, E. Sette, J.G. Capone, M. Cavallo, M. Farneti, E. Granieri, V. Tugnoli (Ferrara, Italy) Hemifacial spasm (HFS) is caused by vascular compression of the facial nerve at its root exit zone from the brainstem. Microvascular decompression (MVD) is a surgical treatment option that offers the prospect of a definitive cure for HFS. Intraoperative monitoring of abnormal muscle response has been used to predict MVD effectiveness. In patients with HFS Blink Reflex (BR) recorded in laboratory shows abnormal R1 diffusion in inferior facial muscles. BR has recently been introduced as a feasible technique during intraoperative monitoring (IOM) of facial nerve function. We evaluated intraoperative feasibility and modifications of BR during MVD for HFS in 8 patients. BR was recorded in 7/8 patients. R1 recorded from inferior facial muscles (orbicularis oris, mentalis muscles) disappeared in 3/7 patients, while it decreased in amplitude during surgery in 4/7 patients. HFS was completely resolved at early follow up evaluation (one week after surgery) in all patients with intraoperative loss of R1 from inferior facial muscles; in the other 4 patients HFS resolution was heterogeneous. Intraoperative BR monitoring can be a complementary technique during HFS surgery to optimize the MVD. doi:10.1016/j.clinph.2014.10.115

97. Ilium chondromyxoid fibroma misdiagnosed as radiculopathy during pregnancy—G. Stipa, A. Luzzati, G. Scotto, P. Chiarini, P. Floridi (Terni, Italy, Perugia, Italy) Chondromyxoid fibroma is a rare benign bone tumor, often misdiagnosed. A 39 years old woman, during first months of pregnancy, referred bilateral lumbar pain, with irradiation to the right leg, and painful paresthesias with radicular distribution (bilateral L5/S1). Symptomatology modified with a circadian rhythm, with a nocturnal exacerbation. Clinical examination documented: a positive right Lasegue sign, an absence of achilleum reflex, and tenderness at the sacroiliac articulation. Before pregnancy, patient presented recurrent episodes of radicular pain at right L5/S1 level. MRI showed hernia discal protrusions at the L4–L5 and L5–S1 levels, while electrophysiologic study exhibited a bilateral chronic radiculopathy L5–S1. After spontaneous miscarriage, patient underwent to another MRI, with extension to pelvis. This exam showed a multiloculated lytic lesion at right ilium level. A CT pointed out a cortical distruption, and extension to adjacent gluteal region. Bioptic material suggested a probable diagnosis of chondromyxoid fibroma, but only surgical excision and definitive histology confirmed this suspect. Ilium localization of this rare tumor made diagnosis difficult and often mistaken with other pathologies. doi:10.1016/j.clinph.2014.10.116