Central Nervous System- Basic Neuropathology

Question No. 9. The Answer is: (B)- Truncal ataxia.

Discussion: Truncal ataxia is resulted from the disturbances of balance manifested chiefly by a lack of coordination of the paraxial muscles. It is a particular feature of midline cerebellar lesions. The patient may be unable to sit or stand without support. It is usually an ominous sign indicative of either midline cerebellar degeneration with no likehilood of recovery, or a midline cerebellar tumor. Most, but not all, medulloblastomas arise in the midline and may cause truncal ataxia.Gait ataxia and intentional tremor is often caused by lesions in the posterior lobe of the cerebellum. Lesions in the anterior lobe of the cerebellum are most likely to cause limb ataxia. “Locked-in” syndrome refers to a clinical condition that the patient is conscious but unable to respond adequately. The patient is muted and paralyzed and is only able to blink. It is classically associated with central pontine myelinolysis.

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