Olivopontocerebellar atrophy is a neurodegenerative syndrome that arises spontaneously or through familial inheritance. This disease manifests as a part of other disorders, namely multiple system atrophy (MSA) and spinocerebellar ataxia (SCA).
Olivopontocerebellar atrophy (OPCA) is a progressive disease, the sporadic form of which is now known as multiple system atrophy with cerebellar features (MSA-C), a subtype of multiple system atrophy (MSA). Its etiology is unknown. The inherited form of OPCA does not follow a single inheritance pattern which is, although, frequently autosomal dominant. Patients who present with the inherited form may have evidence of the illness in their family history. OPCA usually occurs in the middle aged, but the inherited form may develop in younger individuals. It rarely transpires after the seventh decade of life .
OPCA results from atrophy of structures in the brainstem and the cerebellum, thus its symptomatology is based on the dysfunction of these areas. There are several systems affected by OPCA, and the severity of symptoms worsens as the disease progresses. Autonomic dysregulation, if present, includes postural hypotension and gastrointestinal upset . Genitourinary complaints range from urinary symptoms such as retention or incontinence to sexual dysfunction . Pain may be experienced by a minority of patients.
Neurological symptoms and signs include worsening ataxia (one of the earliest signs), dysarthria, uncoordinated limb movements, unstable gait, hyperactive reflexes, and additional pyramidal as well as extrapyramidal manifestations . Signs of parkinsonism such as cogwheel rigidity, postural instability, and tremor may be observed as the disease progresses. In addition, cognitive impairment and neuropathy have been reported.
Ocular dysfunction has been described, in the form of nystagmus, abnormal saccadic eye movements, as well as eye pathologies such as retinopathy . Patients may experience dysphagia and recurrent laryngeal nerve paralysis, which causes stridor and can be rapidly fatal . They are also at risk of aspiration, malnutrition, and traumatic injury from falls.
Patients with OPCA are prone to a number of sleep disturbance disorders such as rapid eye movement (REM) sleep behavior disorder RBD . Furthermore, they have an increased susceptibility to psychiatric conditions such as depression and dementia.
Diagnosis of olivopontocerebellar atrophy (OPCA) entails: