brain stem lesions Flashcards
common causes of brain stem lesions (6)
- strokes (most common)
- traumatic injuries
- inflammatory diseases and infectious diseases
- tumors
- degenerative disorders
- cranial nerve disorders
UMN lesion
- upper motor neuron
- a lesion that occurs in the upper portion of the motor neuron pathway (2nd order)
- lesion on pathway that controls alpha motor neuron
- near cortex, brainstem, medulla, spinal cord
LMN lesion
- lower motor neuron
- a lesion that occurs in the lower portion of the motor neuron pathway (1st order)
- damage to the alpha motor neurons
paralysis by lesion of LMN
- flaccid - the muscle does nothing (“dead”)
- atrophy - wasting away of the muscle
- fasciculation - spontaneous contraction (twitching)
paralysis by lesion of UMN
- spastic - hypersensitive, reflexes, extra tone in the muscles
medial medullary lesion (alternating hypoglossal hemiplegia) can affect
- corticospinal tract
- medial lemniscus
- hypoglossal nerve
what are the symptoms caused by the medial medullary lesion affecting the corticospinal tract?
contralateral hemiplegia of the body (opposite side of the lesion)
what are the symptoms caused by the medial medullary lesion affecting the medial lemniscus?
contralateral loss of touch, pressure, vibration, and joint position sense in the limbs
what are the symptoms caused by the medial medullary lesion affecting the hypoglossal nerve?
ipsilateral wasting of tongue
overall: what are the symptoms (combined) of medial medullary lesion?
- contralateral hemiplegia of the body (opposite side of the lesion)
-contralateral loss of touch, pressure, vibration, and joint position sense in the limbs - ipsilateral wasting of tongue
lateral medullary lesion (wallenberg syndrome) can affect:
- descending V
- spinothalamic tract
- nucleus ambiguus
- inferior cerebellar peduncle
what symptoms are caused when there is a lateral medullary lesion affecting the descending V?
ipsilateral loss of pain and temperature sensation from face
what symptoms occur when there is a lateral medullary lesion affecting the spinothalamic tract?
contralateral loss of pain and temperature sensation from trunk and limbs
what symptoms occur when there is a lateral medullary lesion affecting the nucleus ambiguus?
- dysarthria
- hoarseness
- dysphagia
- loss of gag reflex
- ipsilateral paralysis of laryngeal and pharyngeal muscles
what symptoms occur when there is a lateral medullary lesion affecting the inferior cerebellar peduncle?
- ipsilateral dystaxia
- ipsilateral dysmetria
overall: what are the symptoms of a lateral medullary lesion?
- ipsilateral loss of pain and temperature sensation from face
- contralateral loss of pain and temperature sensation from trunk and limbs
- dysarthria
- hoarseness
- dysphagia
- loss of gag reflex
- ipsilateral paralysis of laryngeal and pharyngeal muscles
- dystaxia
- dysmetria
- ipsilateral
medial pontine lesion can affect:
- corticospinal tract
- corticobulbar tracts
- medial lemniscus
- abducent nerve roots (pathway)
- base of pons
what symptoms occur when there is a medial pontine lesion affecting the corticospinal tract?
contralateral hemiplegia of trunk and limbs
what symptoms occur when there is a medial pontine lesion affecting the medial lemniscus?
contralateral loss of touch, pressure, vibration, and joint position sense in limbs
what symptoms occur when there is a medial pontine lesion affecting the abducent nerve root (pathway)?
ipsilateral paralysis of lateral rectus (eye cannot abduct)
what symptoms occur when there is a medial pontine lesion affecting the base of pons?
ipsilateral ataxia of limbs and gait
overall: what are the symptoms of a medial pontine lesion?
- contralateral hemiplegia of trunk and limbs
- contralateral loss of touch, pressure, vibration, and joint position sense in limbs
- ipsilateral paralysis of lateral rectus (eye cannot abduct)
- ipsilateral ataxia of limbs and gait
a lateral pontine lesion can affect:
- motor nucleus of trigeminal
- chief sensory nucleus of trigeminal
- spinothalamic tract
- middle cerebellar peduncle
what symptoms occur when there is a lateral pontine lesion affecting the motor nucleus of trigeminal?
ipsilateral paralysis of muscles of mastication, deviation of jaw
what symptoms occur when there is a lateral pontine lesion affecting the chief sensory nucleus of trigeminal?
ipsilateral facial hemianesthesia
what symptoms occur when there is a lateral pontine lesion affecting the spinothalamic tract?
contralateral loss of pain and temperature sensation from trunk and limbs
what symptoms occur when there is a lateral pontine lesion affecting the middle cerebellar peduncle?
ipsilateral limb and gait dystaxia
overall: what are the symptoms of a lateral pontine lesion?
- ipsilateral paralysis of muscles of mastication, deviation of jaw
- ipsilateral facial hemianesthesia
- contralateral loss of pain and temperature sensation from trunk and limbs
- ipsilateral limb and gait dystaxia (lack of muscle coordination in walking)
a ventral midbrain lesion (weber syndrome, alternating oculomotor hemiplegia) can affect:
- corticospinal tract
- corticobulbar tracts
- oculomotor nerve roots
what symptoms occur when there is a ventral midbrain lesion affecting the corticospinal tract?
contralateral hemiparalysis of trunk and limbs
what symptoms occur when there is a ventral midbrain lesion affecting the cortibulbar tract?
contralateral weakness of lower face, tongue, palate
what symptoms occur when there is a ventral midbrain lesion affecting the oculomotor nerve roots?
ipsilateral oculomotor nerve paralysis, eye abduction and depression, ptosis, dilated pupil
overall: what are the symptoms of a ventral pontine lesion?
- contralateral hemipareisis of trunk and limbs
- contralateral weakness of lower face, tongue, palate
- ipsilateral oculomotor nerve paralysis, eye abduction and depression, ptosis, dilated pupil
impact of brain stem lesions on dental treatment
- communication challenges
- swallowing difficulties and risk of aspiration
- patient positioning
- oral hygeine
