- Machado-Joseph Disease
- Magnetic Resonance Imaging (MRI)
- Megalencephaly
- Melodic Intonation Therapy
- Ménière's Disease
- Meninges
- Mental Retardation
- Meralgia Paresthetica
- Metachromatic Leukodystrophy
- Microcephaly
- Mitochondrial Myopathies
- Modafinil
- Moebius Syndrome
- Monomelic Amyotrophy
- Motor Neuron Diseases
- Movement Disorders
- Moyamoya Disease
- Mucopolysaccharidoses
- Multi-infarct Dementia
- Multifocal Motor Neuropathy
- Multiple Sclerosis
- Multiple System Atrophy
- Muscular Dystrophy
- Myasthenia Gravis
- Myasthenia, Congenital
- Myoclonus
- Myofibrillar Myopathy
- Myopathy
- Myotonic Dystrophy
