Benedikt's syndrome, all are true except :
Answer is D (Lesion at the level of the pons): Benedict's syndrome also known as dorsal mid brain syndrome results from a lesion in the midbrain tegmentum / red nucleus. It is not a pontine syndrome. In benedict's syndrome injury to the red nucleus midbrain results in ipsilateral occulomotor palsy and contralateral tremor ,chorea and athetosis. -- Harrison Benedikt's s ndrome / Dorsal midbrain s ndrome The dorsal midbrain syndrome or Benedikt's syndrome results from a lesion in the red nucleus or tempmentum of midbrain. It is caused by occlusion of the paramedian / penetrating branches of the basilar or posterior cerebral aery or both. Signs include Ipsilateral occulomotor paresis / ptosis and dilated pupil (damage to fascicle of 3rd CN including parasympathetic fibres) Contralteral involuntary movement -- tremor , chorea , athetosis ( damage to red nucleus interrupts fibers from opposite cerebellar hemisphere ) Contralateral hemiparesis may be present if lesion extends ventrally (damage to descending coicospinal tract ) Contralateral hemianaesthesia may be present if lesion extends laterally (damge to spinothalamic tract and medial meniscus ) Other Midbrain syndromes in association with injury to fascicle / nucleus of CN Ill: Harrison 17th/ 193 Weber's syndrome (Injury to cerebral peduncle) Nothnagel's syndrome (Injury to superior cerebellar peduncle) Claude's syndrome (Injury to red nucleus + superior cerebellar peduncle) * * 1psilateral occulomotor palsy Contralatral hemiparesis * * 1psilateral occulomotor palsy. Contralatral cerebellar ataxia * * Ipsilateral occulomotor pasly Contralateral cerebellar ataxia tremor, chorea, athetosis (Benedikt's + nothnogel's)
Contralateral tremor
3rd nerve palsy
Involvement of the penetrating branch of the basilar aery
Lesion at the level of the pons