Abstract A neuropathological report of Madras type of motor neuron disease (MMND) is presented and the dif- ferences from other forms of MND are discussed. An 18- year-old girl presented with nerve deafness and slowly progressive bulbo-spinal muscular atrophy, characteristic of MMND. Post-mortem examination of the spinal cord showed a severe loss of anterior horn cells, prominent di- latation of vessels, diffuse, but sparse sprinkling of mi- croglial cells and lymphocytes, and demyelination and sclerosis of the ventrolateral columns. Neuronal depletion and marked gliosis was noted in the cochlear nucleus on both sides, while other bulbar motor nuclei were also in- volved. The cochlear nerve showed demyelination and ax- onal loss. Trigeminal and vestibular ganglia revealed fea- tures of ganglionitis. The possibility of an inflammatory aetiology for MMND needs to be considered. Introduction In 1970, Meenakshisundaram et al. [11] from South India, described a special variant of motor neuron disease (MND) in the young, which was referred to as Madras pattern of MND (MMND) [11]. This disease is clinically characterized by a progressive yet benign course, younger age at onset, absence of familial occurrence, persistent asymmetric limb weakness, involvement of bulbar and fa- cial nerve nuclei in nearly two third of the patients, sen- sorineural deafness in one third of cases and evidence of pyramidal tract involvement. Curiously, all these cases have been reported clustering around the South Indian states of Tamil Nadu and Karnataka [4, 6, 8]. Neurologists in other states of India have not seen similar patients, ex- cept an isolated report from Western India [17]. Elec- tromygoraphic studies have revealed features of wide- spread chronic partial denervation with normal conduc- tion, suggesting spinal motor neurons as the site of degen- eration. Absence of all components of brain stem auditory evoked response (BAER) bilaterally and preservation of cochlear microphonics by electrocochleography indicated loss of vestibulocochlear nerve fibers or the sensory cells in the spiral ganglion as the basis for deafness [17]. Cere- bellar and other sensory signs are absent. We report a necropsy study of the first case of MMND to gain a better understanding of the pathomorphological lesions in the brain and spinal cord, and give a brief correlation with the clinical features. Case report On 2 April 1991, a 14-year-old girl presented to the neurological services of National Institute of Mental Health and Neurosciences, Bangalore, South India, with a 6-year history of progressive hear- ing impairment as well as weakness of hands and difficulty in swallowing appearing within the previous 1.5 years and slurring of speech over the previous 6 months. She was from Karnataka State (South India) and belonged to a low socio-economic group. She was the second child of a consanguineous marriage, a full- term normal delivery and had normal developmental milestones. She attended kindergarten but her scholastic performance slowly declined and she discontinued her education. She started taking a longer time to perform the tasks that she was easily performing before. There was no emotional incontinence. The hearing defect was slowly progressive, more on the left side. The patient com- plained of a continuous ‘buzzing noise’ in the right ear for the past 1 month. During the previous 6 months, she had slurred speech, some- times incomprehensible, and drooling of saliva. She had difficulty in eating solid foods. There was no nasal regurgitation. She com- plained of weakness of her hands, difficulty in pumping water, mixing food, buttoning a blouse and threading a needle. The patient had received the regular regimen of vaccinations. There was a past history of a fall in an alleged accident 6 years pre- vious, yet the nature of fall and subsequent events were unavail- S. K. Shankar · M. Gourie-Devi · Lalita Shankar · T. C. Yasha · Vani Santosh · Sarala Das Pathology of Madras type of motor neuron disease (MMND) – a histological and immunohistochemical study Acta Neuropathol (2000) 99 : 428–434 © Springer-Verlag 2000 Received: 14 May 1999 / Revised, accepted: 29 July 1999 CASE REPORT S. K. Shankar () · L. Shankar · T. C. Yasha · V. Santosh · S. Das Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560 029, India e-mail: shankar@nimhans.kar.nic.in, Tel.: +91-80-6642121 ext 220, Fax: +91-80-6631830 M. Gourie-Devi Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560 029, India