Neurological complications due to beta-propiolactone (BPL)-inactivated antirabies vaccination: Clinical, electrophysiological and therapeutic aspects

Seventy six patients with neuroparalytic accidents due to antirabies vaccination (ARV) with BPL vaccine were studied. The mean age of incidence was 26.9 ± 15.7 years. The suspected source of infection was by the bite of a dog in 72 (97.3%) out of 74. The mean duration of interval between the first dose of ARV and onset of neurological deficits was 12.2 ± 8.4 days. The number of doses was 7 or less in 49 (65.3%) cases and more than 7 in 26 (34.7%) cases. With regard to neurological deficits, 6 (7.9%) had encephalopathy, 23 (30.3%) had encephalomyeloradiculopathy, 7 (9.2%) had myelopathy, 21 (27.6%) had myeloradiculopathy, 18 (23.7%) had polyradiculopathy and one had bilateral 7th cranial nerve palsies. Lumbar CSF analysis was done in 67 patients and was abnormal in 47 (70.1%) patients in the form of pleocytosis or raised protein or both. EEG, done in 30 patients, was abnormal in 13 (43.3%) and the abnormalities were not related to clinical features in 6. Electroneuromyography (ENMG) was done in 25 and was abnormal in 21 cases. Visual evoked potentials (VEP) was done in 11 cases and was abnormal in two. Sixty eight patients received steroids and 17 patients received cyclophosphamide in addition to steroids, 14 during the first admission and 3 during follow up when the recovery with steroids was not satisfactory. The therapeutic results were better in those who received cyclophosphamide and was statistically significant. Fourteen (18.4%) patients died and 6 were autopsied. The pathological features were essentially myeloradiculopathies, with variable degree of encephalic involvement. Two showed distinct necrotising myelopathy of immune type.