Sub-acute sclerosing panencephalitis (a report of 43 cases).
Spinal muscular atrophy (S.M.A.) is a distinct entity characterized by involvement of the alpha motor neurones, manifested clinically by atrophy (wasting due to anterior horn cell affection), fibrillations and areflexia, with electrophysiological and pathological evidence of the lesion, being at the anterior horn cell. In general, the proximal muscles are maximally involved, and the prognosis varies according to the age of onset. This disease entity differs from motor neurone disease and muscular dystrophy, although some varieties of the former bear a close resemblance, to some forms of the latter two conditions.
Cases of S.M.A. were first reported by Heubner in 1887 and later by Wolfhart in 1942 and Brandt in 1950. However, Kugelberg and Welander, reporting on their 12 cases, first coined the term, "juvenile muscular atrophy simulating muscular dystrophy". Although, the definition of spinal muscular atrophy precludes involvement of the corticospinal tracts, a few stray cases with such an involvement have been reported. Earlier reports on this disease stressed upon the predominant proximal muscle involvement, simulating limb girdle dystrophy; now however, various patterns of muscle involvement, as well as various inheritance patterns have been described.
The most comprehensive study, to date, on spinal muscular atrophy is the 1976 International Collaborative Study,,  where extensive data on genetic and clinical patterns and investigations have been collated from 507 patients and their corresponding 415 families.
Emery and Pearn modified the classification to include all the various forms which have been described viz.:
(a) Infantile form: This is synonymous with Werdnig-Hoffman's disease and has an onset at birth, with an acute progress.
(b) Intermediate form: This is an arrested variety of Werdnig-Hoffman's disease with onset at 3-18 months of age and slow progress.
(c) Juvenile form: This is the classical "Wolfhart-Kugelberg-Welander" type of S.M.A. The onset can vary from infancy to adult life and the disease is progressive.
(d) Adult form: This has a late onset and a chronic progression.
II-Distal form: with onset in early childhood and a chronic progression.
III-Fazio Londe form: with progressive bulbar and spinal involvement.
IV - Fascioscapulohumeral form: with onset from 10-1a years of age and a chronic course.
V - Scapuloperoneal form: which can occur at any age and has a chronic course.
Forty-four cases of spinal muscular atrophy admitted to the Department of Neurology, K.E.M. Hospital Bombay-12, diagnosed clinically and by investigations, form the subject of the present paper. The classification of these cases is done according to the guidelines, suggested by Emery.
Of the 44 cases 36 cases were of proximal S.M.A. (2 infantile, 3 of the intermediate, 18 juvenile, 13 adult) 5 distal, 2 fascioscapulohumeral and one of the scapuloperoneal type.
Proximal S.M.A. (36 cases)
Infantile form (Werdnig-Hoffman type) (2 cases)
In the infantile group, there was one male and one female patient, and the age at examination was 4 years and 9 months respectively, the onset being from birth in both. The female child had a strong family history, three of her female sibs having similar affection (2 died at 31/2 months of age, and one sib at 31/2 months of age had not achieved any milestones). This patient was quite moribund at the time of examination, justifying her inclusion in this group.
The presenting features of flaccid, jerkless, paralysis in all 4 limbs, without evidence of any corticospinal tract involvement compared well with those of Pearn and Wilson. However, the absence of consanguinity and congenital deformities in our cases was odd.
The C.P.K. was normal, and the E.M.G. and muscle biopsies were suggestive of anterior horn cell affection.
Intermediate form (3 cases)
Pearn and Wilson claimed that 20% of cases of spinal muscular atrophy in children belonged to this group. Others,  do not recognise this as a separate form, but instead, group together cases of S.M.A. with onset before 4 years, thus including some cases of the juvenile type.
All the 3 cases in our series were females and the age of onset was from 3 to 15 months, with delayed motor milestones, difficulty in walking being the presenting symptom in all. The predominant clinical features were weakness of all 4 limbs, hypotonia, foot and wrist drop, with total areflexia. However in one case, the wasting was predominantly in the lower limbs, while in the other it was in the upper limbs proximally. The associated interesting features were hypertrophied calves in one case (with absent reflexes, normal C.P.K. and E.M.G. and muscle biopsy indicative of an anterior horn cell lesion) and kyphoscoliosis together with an extensor plantar in the other case. One case at the age of 7 had a low I.Q.
C.P.K. was normal in all patients, while the E.M.G. and muscle biopsy in all showed denervation changes, suggestive of an anterior horn cell involvement. The age of survival was from 5-7 years.
Our cases when compared with the 19 index patients, with onset before 2 years and a chronic course as described by Bundey and Lovelace differ in the absence of fasciculations, facial weakness, pes cavus and sib affection. The associated feature of kyphoscoliosis is comparable.
Juvenile and adult forms
(18 and 13 cases)
[Table - 1],[Table - 2] and [Table 3].
The incidence of consanguinity in our cases is comparable with other authors.,  The familial incidence is however much less than that found by others., , ,  The case with a ?X-linked inheritance differed from that of Tsukagoshi et al in the absence of bulbar involvement.
The preponderant shoulder girdle involvement found in our cases in unusual., 
Namba et al reported preservation of distal musculature; however, we noted marked distal involvement in four of our cases. Gardner-Medwin et al have also documented similiar findings.
The muscles maximally involved in the upper limbs were the spinati and deltoids, and in the lower limbs the peronei and hamstrings. The latter is unusual. The other notable feature was the affection of the brachioradialis muscle, in two patients, which has previously been reported only by Gardner-Medwin et al.
The association of facial weakness has been noted previously. The absence of ophthalmoplegia and bulbar involvement in our cases was an oddity.
One of the cases with neck and facial muscle involvement showed pronounced distal weakness (foot drop) in addition to proximal muscle involvement, simulating a fascioscapuloperoneal pattern of spinal muscular atrophy.
The incidence of fasciculations was less than that found by previous workers., , , 
The occurrence of an extensor plantar response in only one patient is unusual when compared with others.,  The incidence of tremors and pes cavus in one patient each, is comparable.,  The patient with pes cavus had thickened nerves without evidence of Hansen's disease. He had an onset of weakness, proximally in the lower limbs. His E.M.G. was suggestive of anterior horn cell affection; in addition, there was minimal diminution of the conduction velocity. Biopsy revealed an absolutely normal sural nerve in the presence of denervation atrophy of the muscles.
The calf hypertrophy noted, has been reported previously.,  Bouwsma and Wigngarden found preponderance of calf hypertrophy in males, a high percentage of whom had elevated C.P.K. levels. However, in our 2 patients with calf hypertrophy, one was a female and both had normal C.P.K. levels.
Only one patient showed a pseudomyopathic pattern on the biopsy as compared to an 18% incidence of a mixed pattern found in the International Collaborative Study.
The E.C.G. changes seen in three patients may be due to an underlying cardiomyopathy, which has been reported in this disease.,  One of the cases with an adult onset had predominant involvement of the quadriceps and gastrocnemius. This could fit into the chronic neurogenic quadriceps amyotrophy described as a forme-fruste of spinal muscular atrophy Furukawa et al.' 
Distal Type (5 cases)
Classically, this type of S.M.A. shows symmetrical, distal involvement of the lower limbs, with absence of pyramidal and sensory signs. The age of onset is early, with the survival period extending over many years. Magee et al, however, described a syndrome of bulbar palsy with progressive distal muscular atrophy developing many years later.
All five patients in our series were males; the age of onset was 8 years in one and from 20-27 years in the remaining. The symptoms were preceded by fever in one and two had a history of sib affection.
Symmetrical distal weakness was seen in four, 2 of whom had all 4 limb and 2 only upper limb involvement. One case had asymmetrical lower limb involvement. Our 2 cases with upper limb involvement were similiar to those described by Singh et al in that one had a precipitant of fever, and both had an early onset; however, there was no asymmetry of involvement or tremors. Fasciculations were seen in one case. One patient with lower limb involvement had calf hypertrophy, facial involvement and absent reflexes, a C.P.K. of 228 units, a neurogenic pattern on the E.M.G. and a combined picture in the biopsy. This particular case is differentiated from distal myopathy by the early age of onset and the neurogenic picture seen in the E.M.G. and muscle biopsy.
The reflexes were absent in all, except one, and all had a normal plantar response. C.P.K. was abnormal in only one patient. The E.M.G. was typical of anterior horn cell affection in all, and the muscle biopsy showed denervation atrophy in all, one of whom showed a pseudomyopathic pattern in addition. The survival rate was from 1-8 years in 4, and 61 years in one.
Fascioscapulohumeral Type (2 cases)
Of the 2 cases in this group, one was a male and one female and the age of onset was 2 and 13 years respectively, which is lower than that reported by others.,  The neck and face muscles were involved in both. The trapezius, supra and infraspinatus, pectoralis, latissimus, rhomboids, serratus anterior and deltoids were the muscles maximally affected. Reflexes were lost in both, while the plantar response was equivocal in one.
Both cases had a normal C.P.K., a myogenic pattern in the E.M.G. and denervation atrophy seen in the biopsy. Interestingly, the male patient had a family history of Duchenne's dystrophy (in his brother) and this, most probably, was responsible for the associated E.C.G. abnormality (tall R waves in anterior leads with T wave inversion).
Scapuloperoneal Type (1 case)
This patient was a male who developed distal weakness in the lower limbs after a febrile episode at the age of four years. Seven years later, he developed proximal weakness. When he was examined at the age of 15, he had symmetrical involvement of the scapular and peroneal group of muscles, normal sensations and a flexor plantar response. The C.P.K. and the muscle biopsy were normal but the E.M.G. was suggestive of anterior horn cell affection.
This case differs from those reported by Kaeserand Takahashi et al in the very early age of onset, absence of bulbar involvement and cardiomyopathy. Rather it seems to dovetail with the cases reported by Mercelis et al.
The authors thank Dr. C. K. Deshpande, Dean, Seth G.S. Medical College and K.E.M. Hospital, for his kind permission to use the hospital records and to publish this paper. Thanks are also due to the resident staff of the Department of Neurology for their help in the study of the material.