D. Nagaraja

Acute idiopathic axonal neuropathy (AIAN): a clinical and electrophysiological observation

Twenty patients (M:F 15:5) with electrophysiological evidence of predominant axonal lesion and fulfilling clinical criteria for Guillain Barré Syndrome were observed during a period of 6 years (1985–1990). Their mean age was 27.5 years (range 5–55). Seven patients had antecedent febrile illness. Peak motor deficit was reached at a mean period of 6.5 days (range 2–21 days). All the patients had distal muscle weakness out of proportion to proximal muscle weakness. Facial paresis (13 patients), bulbar palsy (2), respiratory failure (1), sensory deficits (7) and dysautonomia (1) were other salient features. CSF analysis revealed albuminocytological dissociation in 12 patients. One patient died and in the remaining patients the recovery was delayed and incomplete. Presence of predominant distal muscle wasting and weakness, low amplitude CMAP or inexcitable nerves, absence of conduction block or significant temporal dispersion, normal or only slightly reduced conduction velocity and evidence of poor recovery suggest that the primary pathology in these patients may be axonal degeneration. These cases may represent a distinct entity and need to be differentiated from the more commonly observed acute idiopathic demyelinating neuropathy.

Multi-infarct dementia: a computed tomographic study

ABSTRACT— CT Scan of 30 patients with multi‐infarct dementia (MID) were compared with age‐ and sex‐matched controls. Infarcts were seen in 93% of MID cases and 10% of controls. A marked difference in the occurrence of white matter low attenuation was seen between the groups. All the parameters of cerebral atrophy studied showed a statistically significant correlation with the presence of dementia.

Epidemic of acute inflammatory myopathy in Karnataka, South India : 30 cases

Thirty patients of acute inflammatory myopathy were seen over a short period of 11 months (February to December 1986) at NIMHANS, Bangalore, South India. The characteristic features were: short febrile illness followed a few days later by myalgia, edema of extremities, severe motor weakness and involvement of multiple other systems. Their mean age was 32.3 years and M:F ratio was 4:1. CK levels were increased in all. EMG done in 23 patients showed spontaneous activity in 13 and myopathic pattern in all. Nerve conduction studies revealed abnormalities in 12 cases. Muscle biopsy done in 21 patients showed varying degree of myophagocytosis and inflammatory infiltrates. All patients received steroids for only 6–8 weeks. Twenty‐two patients recovered, one developed residual disability and 7 patients died during the acute phase. None of the survivors has developed relapse so far. Such cases with monophasic illness in clusters have not been reported earlier.

Angiographic profile of ischaemic stroke in the young — Study of 143 cases

The incidence of stroke in the young is higher in the Indian subcontinent than in the West, but the precise cause is not known. Previous angiographic studies in cases of young stroke have yielded variable results. The present angiographic study of 143 cases of young stroke (under 40 years of age) showed a high incidence of abnormality (71%). The lesions included atherosclerotic disease of the internal carotid artery (68%), stenosis/occlusion of the major intracranial vessels (37%) and small-vessel disease. Tandem lesions were common (26%). Primary atherosclerosis is thought to be the cause of young stroke in the Indian population.

PO2.2 Manual Scanning EMG Study of Variability of Motor Unit Potential Parameters

Background: False positive findings are seen in a high percentage of imaging studies in prolapsed intervertebral discs (PIVD) necessitating electro-diagnosis as a confirmatory test in the diagnosis of radiculopathy induced low back pain. Methods: Aim was validation of paraspinal EMG (pEMG) in electrophysiological evaluation of radiculopathy. Detailed neurological examination was carried out in patients with L5/S1 radiculopathy due to PIVD. Peripheral electroneuromyographic studies and pEMG according to Haig’s technique (Muscle & Nerve 1993) were done; in the latter an increased score denoted increased abnormal EMG activity, and needle positions were classed as specific, medial and intermediate. Results: Twenty patients with a mean age of 40.2+10.1 years were studied. Spontaneous activity was analysed in lumbar paraspinal muscles. Mean symptom duration was 1.23+1.2 years. Nineteen (95%) had neurological deficits such as loss of tendon jerks, radicular sensory loss and muscle weakness. On MR, mean L5 and S1 spinal canal diameters were 10.15+2.0 mm and 10.1+2.2 mm, while mean lateral recess diameters were 3.55+1.5 and 5.15+1.35 mm, respectively. Mean spontaneous EMG scores (at L5/S1 levels in specific EMG position were 1.45+1.7 and 1.15+1.46 respectively. Statistical analysis using Chi-square test showed a highly significant difference in pEMG activity in S1 specific EMG position between subjects with normal and abnormal lateral recesses at the corresponding segment (p = 0.0012). No other statistically significant association was seen. Conclusions: In this study pEMG had a higher sensitivity for abnormalities than either peripheral EMG or imaging studies. The S1 specific pEMG insertion site correlated only for S1 lateral recess MRI abnormalities.

P01.1 A comparative study of single fiber electromyography and ice pack test in the evaluation of ptosis

Background: Establishing precise aetiology for ptosis has therapeutic implications. Few studies have reported ice pack test (IPT) to be comparable in sensitivity to repetitive nerve stimulation (RNS) test with negligible false positives in myasthenia gravis (MG). However, RNS test has low sensitivity and there are no studies comparing IPT with single fiber electromyography (SFEMG). Objective: To compare IPT with SFEMG in the evaluation of ptosis of myasthenic origin from other causes. Patients and methods: Fifty patients manifesting with ptosis and normal/inconclusive RNS test were studied. SFEMG of Frontalis and Orbicularis oculi (26) muscles was carried out and 20 potential pairs were sampled for jitter analysis. IPT was performed by placing ice cubes, wrapped in a gauze piece, over lightly closed, ptotic eye for 5 min. Palpebral fissure width, before and immediately after the IPT, was measured on straight-ahead gaze. IPT was considered positive if the palpebral fissure width increased by 2 mm or more. The cause of ptosis was ascertained based on clinical profile, neostigmine test (46), muscle biopsy (9), imaging studies and therapeutic response to steroids. Results: The final aetiology for ptosis was: MG-24 (ocular-15, oculobulbar-5, mild generalized-4) and nonMG causes-26 (ocular myopathy-10, mitochondrial myopathy-5, others-11). Neostigmine test was positive in 19/22 patients in MG group and 1/24 in non-MG group. In MG group, SFEMG and IPT were abnormal in 23/24 and 20/24, respectively, with concordance in 19/24 patients while in non-MG group, they were abnormal in 4/26 and 5/26, respectively, with concordance in 21/26 patients. Conclusion: IPT is a useful adjunct in the evaluation of ptosis. However, results of IPT need to be confirmed by SFEMG and other investigations.