Benedikt syndrome: causes, symptoms, diagnosis and treatment of this stroke

By Cristiano Antonino On Aug 22, 2022

Benedikt syndrome (also called paramedian midbrain syndrome), is a rare type of brain stroke that results in damage to the midbrain tegmentum: this is manifested by a series of neurological symptoms and signs

Causes of Benedikt syndrome

Benedikt syndrome is caused by an injury (ischaemic, haemorrhagic, tumour or tuberculosis) to the midbrain tegmentum and cerebellum.

In particular, the median area is compromised.

It often results from occlusion or haemorrhage of the posterior cerebral artery or paramedian penetrating branches of the basilar artery.

Affected neuroanatomical structures include the oculomotor nucleus, red nucleus, corticospinal tracts and decussation of the superior cerebellar peduncle.

Benedikt syndrome is characterised by the presence of:

paralysis of the oculomotor nerve (third cranial nerve);
eyeball looking downwards and outwards;
diplopia;
miosis;
mydriasis;
loss of accommodation reflex;
contralateral loss of proprioception and vibratory sensations;
contralateral hemiparesis;
cerebellar ataxia;
contralateral hemiataxia (hemithremor);
involuntary choreoathetotic movements.

Diagnosis of Benedikt syndrome

Diagnosis is based on symptoms and signs; CT and MRI help confirm the diagnosis and delineate the cause or the vessel or region involved in the stroke.

Differential diagnosis

Benedikt’s syndrome has similar causes, signs and symptoms to Weber’s syndrome; the main difference between the two is that Weber’s is more associated with hemiplegia (i.e. paralysis) and Benedikt’s with hemiataxia (i.e. disturbed co-ordination of movements).

It is also similar to Claude’s syndrome, but is distinguishable in that Benedikt’s has more predominant tremors and choreoathetotic movements while Claude’s is more marked by ataxia.