Guillain-Barré syndrome. A clinical electrophysiological and biochemical study

Fifty-six consecutive patients with Guillain-Barré syndrome representing 49% of all cases of peripheral neuropathy (except those due to diabetes mellitus and leprosy) admitted to the Postgraduate Institute of Medical Education and Research, Chandigarh over a period of three years were studied. All patients developed weakness of limbs within one day to three weeks. Attenuation of deep tendon jerks (98%) paresthesia (66%), cranial nerve involvement (41%) and antecedent infection (32%) were the common clinical features. The common patterns of motor weakness were predominantly proximal in all the four limbs (45%) or predominantly proximal in lower limbs along with distal muscles in upper limbs (29%). Electrodiagnostic studies revealed prolonged distal (motor) latency (82%), reduced motor nerve conduction velocity (74%), sensory nerve conduction abnormality (85%) and evidence of denervation (41%). Evoked motor response of median, ulnar, common peroneal and tibial nerves exhibited significant increase in duration and reduction in amplitude. The maximum incidence of electrophysiological abnormality occurred between four to 12 weeks after the onset of neurological symptoms. Four patients died and 11 showed poor recovery. Long intervals (greater than 3 weeks) between peak deficit and onset of recovery and coexistence of reduced motor nerve conduction velocity with evidence of denervation on EMG were found to be associated with poor recovery.

Effect of protein calorie malnutrition on peripheral nerves. A clinical, electrophysiological and histopathological study

Forty-three children (aged 7 to 62 months) with protein calorie malnutrition (PCM) were studied; 13 had mild to moderate PCM and 30 severe PCM. A reduction of motor nerve conduction velocity and abnormalities of sensory conduction were present in both groups. The abnormality of motor nerve conduction was directly related to the severity of PCM and the presence of hypotonia and/or hyporeflexia. Sural nerve biopsies from both groups were studied for myelinated fibre density, fibre size spectrum, relationship of internodal length with diameter and qualitative light microscopic changes. The biopsies from children with mild to moderate PCM were characterized by a normal developmental change in myelinated fibres with an increasing proportion of medium and large size fibres, a transition from a unimodal to a bimodal distribution and an appropriate relationship of internodal length to fibre diameter. Evidence of mild segmental demyelination was observed in only one patient of this group. In contrast, in the biopsies from children with severe PCM, the normal developmental pattern for myelinated fibre size distribution was impaired with a persistence of small myelinated fibres, and there was a failure of internodal segments on large fibres to elongate with increase in age and significant segmental demyelination in about 50 per cent of cases. Retarded myelination and segmental demyelination probably form the morphological basis for impaired peripheral nerve function in PCM. Short internodes on large diameter fibres may also contribute to this effect.

Prospective study of controlled oxygen therapy. Poor prognosis of patients with asynchronous breathing

Thirty-two patients were evaluated within 24 hours of admission for 36 episodes of acute respiratory failure (arterial oxygen pressure less than or equal to 50 mm Hg). Clinical data, spirometric determinations, blood gas analysis, and synchronization of chest (rib cage) and abdominal (diaphragmatic) breathing movements were studied. All patients were initially treated with controlled oxygen therapy. In 25 episodes the patients recovered without intubation (successes). In nine episodes the patients required intubation and assisted ventilation; two of these patients died. Two patients died without intubation. The 25 successful episodes were compared with the 11 requiring intubation or associated with death (failures). The breathing pattern proved to be the best single factor for predicting success or failure (77 percent correct prediction). The breathing pattern plus the arterial carbon dioxide tension on admission was the best two-factor guide (86 percent correct prediction). Patients with asynchronous breathing and severe hypercapnia are so unlikely to do well with a program of controlled oxygen therapy that preparations for intubation and assisted ventilation should be made on admission and such measures should be instituted at the first sign of deterioration.

Effect of cardiac, pulmonary, and vascular disease on one-minute oxygen uptake

A simplified method for estimation of one-minute oxygen uptake (VO2-1) during treadmill grade walking at vertical power requirements of 250, 750, and 1,000 kg-meters/min was devised, where power=weight (kg) X grade (fractional) X walking speed. All subjects were men. There were 29 controls, 34 subjects with coronary arterial disease (of whom 18 had had myocardial infarction), nine subjects with diffuse pulmonary disease, and four subjects with ischemic vascular disease. Abnormally reduced values for VO2-1 were related to these diseases and, more specifically, to a history of myocardial infarction and (in pulmonary subjects) to reduced single-breath diffusing capacity. Lowest values of VO2-1 for a group were found in ischemic vascular disease. Reduced response of VO2-1 may therefore be caused by central defects of oxygen transport.