Cerebellar Disorders
The neurons in the ventrolateral medulla that generate cough and breathing patterns interact with neural networks in the cerebellum-rostral interposed nucleus, the rostral fastigial nucleus, and the infra-cerebellar nucleus. Therefore, a dramatic reduction in cough frequency is observed after cerebellectomy or lesion of the interposed nucleus (15). In cerebellar neurodegenerative diseases, there is a reduction in the frequency of cough episodes that coincides with cerebellar atrophy. However, in a rare form of autosomal dominant cerebellar ataxia (spinocerebellar ataxia type-5), episodes of spasmodic cough begin 10 to 30 years earlier than the onset of ataxia. It may also be associated with spasmodic dysphonia and tremor. Both spasmodic cough and dysphonia may be caused by laryngeal hyperreactivity and vagal dysfunction. These coughing episodes could be considered reliable markers of familial neurodegenerative disease if there is a previously diagnosed case (16).