Multiple system atrophy (MSA) is a degenerative disease of the central nervous system. It was first described in 1900 by Dejerine and Thomas as olivopontocerebellar atrophy (OPCA), although Menzel described the first case in 1891. Shy and Drager in 1960 described a neurological syndrome with orthostatic hypotension, which was later defined as MSA. Graham and Oppenheimer proposed the term MSA in 1969, suggesting that OPCA, idiopathic orthostatic hypotension, the Shy-Drager syndrome, and striatonigral degeneration are manifestations of neuronal atrophy in overlapping combinations. MSA is a sporadic disease, often misdiagnosed as idiopathic Parkinson's disease. It is more common than previously thought, with 4-22% of parkinsonian brain banks showing MSA. The prevalence is approximately 16.4 per 100,000 population, with a mean age of onset of 53 years and a median disease duration of five years. Both sexes are equally affected. MSA presents with a combination of parkinsonian, autonomic, pyramidal, and cerebellar signs. Clinical features include parkinsonian symptoms, autonomic failure, pyramidal signs, and cerebellar signs. Autonomic symptoms are present in 97% of patients and may precede motor symptoms. Cerebellar signs occur in about half the patients, with gait ataxia being common in OPCA. Pyramidal signs, dysarthria, nystagmus, and impaired vibration sense are also seen. Dysphagia and respiratory stridor may develop later. MSA is often misdiagnosed as Parkinson's disease. Key differentiating features include poor levodopa response, presence of pyramidal or cerebellar signs, autonomic failure, early falls, and rapid clinical deterioration. Intellectual function is preserved, and dementia is not a feature. Plasma noradrenaline levels are normal in MSA, distinguishing it from pure autonomic failure. Pathologically, MSA is characterized by glial cytoplasmic inclusions (GCIs), which are not specific but characteristic of MSA. These inclusions are found in various brain regions and are associated with neuronal loss and gliosis. Neurochemical changes include loss of dopamine, noradrenaline, and serotonin. MRI may show altered signal in the striatum, differentiating MSA from Parkinson's disease. Treatment is mainly supportive, with no curative therapy. Levodopa is ineffective, and supportive measures such as postural hypotension management, anticholinergics for urinary symptoms, and vasoconstrictors are used. Physiotherapy, occupational therapy, and speech therapy are beneficial. MSA is a complex disease withMultiple system atrophy (MSA) is a degenerative disease of the central nervous system. It was first described in 1900 by Dejerine and Thomas as olivopontocerebellar atrophy (OPCA), although Menzel described the first case in 1891. Shy and Drager in 1960 described a neurological syndrome with orthostatic hypotension, which was later defined as MSA. Graham and Oppenheimer proposed the term MSA in 1969, suggesting that OPCA, idiopathic orthostatic hypotension, the Shy-Drager syndrome, and striatonigral degeneration are manifestations of neuronal atrophy in overlapping combinations. MSA is a sporadic disease, often misdiagnosed as idiopathic Parkinson's disease. It is more common than previously thought, with 4-22% of parkinsonian brain banks showing MSA. The prevalence is approximately 16.4 per 100,000 population, with a mean age of onset of 53 years and a median disease duration of five years. Both sexes are equally affected. MSA presents with a combination of parkinsonian, autonomic, pyramidal, and cerebellar signs. Clinical features include parkinsonian symptoms, autonomic failure, pyramidal signs, and cerebellar signs. Autonomic symptoms are present in 97% of patients and may precede motor symptoms. Cerebellar signs occur in about half the patients, with gait ataxia being common in OPCA. Pyramidal signs, dysarthria, nystagmus, and impaired vibration sense are also seen. Dysphagia and respiratory stridor may develop later. MSA is often misdiagnosed as Parkinson's disease. Key differentiating features include poor levodopa response, presence of pyramidal or cerebellar signs, autonomic failure, early falls, and rapid clinical deterioration. Intellectual function is preserved, and dementia is not a feature. Plasma noradrenaline levels are normal in MSA, distinguishing it from pure autonomic failure. Pathologically, MSA is characterized by glial cytoplasmic inclusions (GCIs), which are not specific but characteristic of MSA. These inclusions are found in various brain regions and are associated with neuronal loss and gliosis. Neurochemical changes include loss of dopamine, noradrenaline, and serotonin. MRI may show altered signal in the striatum, differentiating MSA from Parkinson's disease. Treatment is mainly supportive, with no curative therapy. Levodopa is ineffective, and supportive measures such as postural hypotension management, anticholinergics for urinary symptoms, and vasoconstrictors are used. Physiotherapy, occupational therapy, and speech therapy are beneficial. MSA is a complex disease with