Understanding progressive multifocal leukoencephalopathy: links between milky-way appearance and mismatch T2/FLAIR.

Background: Magnetic resonance imaging is essential to diagnose progressive multifocal leukoencephalopathy. The broad radiological spectrum may partially be explained by genetic viral mutations and their differential neurotropism. Recent pharmacovigilance-magnetic resonance imaging studies have provided new insight into pathophysiology and radiological markers of early stages.

Hereditary spastic paraplegia: An "ears of the lynx" magnetic resonance imaging sign in a patient with recessive genetic type 11.

Hereditary spastic paraplegias are an uncommon group of monogenic diseases that include 79 types of genetic disorders. The most frequent cause of recessive hereditary spastic paraplegia is a mutation in the spastic paraplegia gene type 11 followed by type 15. This group is usually associated with non-specific clinical features like cognitive decline and may precede the progressive weakness and spasticity of lower limbs.

The Floccular Syndrome: Dynamic Changes in Eye Movements and Vestibulo-ocular Reflex in Isolated Infarction of the Cerebellar Flocculus.

The cerebellar flocculus is a critical structure involved in the control of eye movements. Both static and dynamic abnormalities of the vestibulo-ocular reflex (VOR) have been described in animals with experimental lesions of the flocculus/paraflocculus complex. In humans, lesions restricted to the flocculus are rare so they can become an exceptional model to contrast with the clinical features in experimental animals or in patients with more generalized cerebellar diseases.