A15. Clinical syndromes of impaired circulation of the vertebrobasilar sys Flashcards
LIST Clinical syndromes of impaired circulation of the vertebrobasilar system
- Vertebrobasilar insufficiency
- Ischemic stroke
- Hemorrhagic stroke (Intracerebral hemorrhage, Subarachnoid stroke)
what forms basilar artery?
vertebral artery
vertebral artery and its branches supply
medulla and the
inferior surface of the cerebellum before forming the basilar artery
basilar
artery supplies
brain stem from the medulla upwards and
divides into
posterior cerebral arteries and posterior communicating arteries
basilar artery divides into
divides into
* posterior cerebral arteries and
* posterior communicating arteries
vertebrobasilar system supplies
- cerebellum,
- pons,
- medulla,
- midbrain,
- thalamus and
- the occipital cortex
As a consequence the
symptoms can vary depending on which areas are affected.
what is Vertebrobasilar insufficiency
VBI is a set of symptoms due to ischemia in the posterior circulation
of the brain
● The symptoms are usually transient and resolves within 24 hours
how are symptoms in Vertebrobasilar insufficiency?
● The symptoms are usually transient and resolves within 24 hours
Vertebrobasilar insufficiency General symptoms
○ Drop attacks (weakness of quadriceps → fall to the ground)
○ Diplopia
○ Dysarthria
○ Dizziness
○ Vertigo
○ Dysphagia
○ Dyequilibrium,
○ ataxia
○ alternating syndromes
Vertebrobasilar insufficiency causes
usually caused by
* atherosclerosis,
* hypertension,
* diabetes,
* smoking,
* dyslipidemias.
* Postural changes, exercise and
dehydration can also cause these
symptoms
treatment of Vertebrobasilar insufficiency
Treatment often includes
* lifestyle changes
* treatment of underlying conditions.
* Patients can also get started on antiplatelet or anticoagulation.
* Angioplasty is a possibility for treatment of vertebrobasilar stenosis.
what can be used as treatment of vertebrobasilar stenosis.
Angioplasty is a possibility
Ischemic stroke
● Causes
○ Atherosclerosis: most common cause, causes stenosis and occlusion
○ Dissection: not so common
○ Vasculitis
○ Embolism: plaques from atherosclerosis
-cardioembolic stroke: due to atrial fibrillation, mural thrombus, CHF
○ Lacunar type: occlusion of small vessels
where do ischemic strokes occur which areas
-
territorial (in the distribution territory of large arteries)
*thrombotic (local atherosclerotic plaque)
*embolic (embolus = plug) -
border zone (in the watershed areas of large vessels,
*hemodynamic causes -
small vessel disease
*lacunar infarct
what is cerebral venous sinus thrombosis?
can the term “stroke” be used to?
This is called cerebral venous sinus thrombosis
addition to arterial disturbances of cerebral blood, venous disturbances of cerebral blood may also occur.
However, the term “stroke” is usually used to denote cerebral blood flow disturbance on the arterial side
what is stroke?
However, the term “stroke” is usually used to denote cerebral blood flow disturbance on the arterial side
can ischemic stroke transform into hemorrhagic stroke?
yes after a few days (more common in cardioembolic stroke)
Hemorrhagic stroke types
Intracerebral hemorrhage
Subarachnoid stroke
Intracerebral hemorrhage
○ Causes:
- hypertension,
- trauma,
- vascular malformations,
- vasculitis,
- drug use
Most common areas where Intracerebral hemorrhage can occur
- putamen,
- thalamus,
- pons and
- cerebellum
Subarachnoid stroke causes
- Traumatic SAH: traumatic brain injury
- Nontraumatic (spontaneous) SAH
Causes
- Ruptured intracranial aneurysms
Most commonly occur in the circle of Willis
Berry aneurysms account for approx. 80% of cases of nontraumatic SAH. - Ruptured arteriovenous malformations (AVM)
- Others: cortical thrombosis, angioma, neoplasm, infection
types of aneurisms in SAH
○ Saccular aneurysms: most common form
○ Fusiform aneurysms, rarely rupture
○ Ruptured aneurysm → SAH
○ Around 2% of aneurysms are located at the VB area
General symptoms of stroke of VB area-
Posterior cerebral artery
- Contralateral hemianopia or quadrantanopia
-
Midbrain findings:
*ipsilateral CN III and IV palsy/pupillary changes,
*contralateral hemiparesis/ hemiplegia (Weber’s syndrome) -
Thalamic findings:
*hemiballismus or chorea with hemisensory disturbance,
*amnesia,
*decreased levels of consciousness
bilateral Posterior cerebral artery stroke symptom
bilateral: cortical blindness or prosopagnosia (inability to recognize faces)
cortical blindness: loss of vision without any ophthalmological causes and with normal pupillary light reflexes due to bilateral lesions of the striate cortex in the occipital lobes
occlusion of cortical vessels- Posterior cerebral artery stroke symptom
homonymous hemianopia, sparing of macular vision
Posterior cortical infarction in dominant hemisphere in Posterior cerebral artery symptom
problems in naming colors and
objects
General symptoms of proximal Basilar artery stroke
Proximal:
* impaired EOM,
* vertical nystagmus,
* reactive miosis,
* hemi- or quadriplegia,
* dysarthria,
* locked-in syndrome,
* coma
General symptoms of distal Basilar artery stroke
- somnolence,
- memory and
- behaviour abnormalities,
- oculomotor deficit
General symptoms of stroke in Pontine branches of Midbrain
Benedikt’s syndrome
■ Complete or partial oculomotor palsy
■ Contralateral tremor (damage of red nucleus)
General symptoms of stroke in Pontine branches of pons
■ Abducens nerve palsy, ipsilateral facial weakness
■ Contralateral sensory loss (light touch, proprioception)
■ If also contralateral hemiplegia: Millard-Gubler syndrome
Millard-Gubler syndrome
also known as Ventral pontine syndrome (Millard-Gubler syndrome)
Pontine stroke can cause
* ipsilateral loss of function of the facial and abducens nerves with
* contralateral hemiparesis (Millard-Gubler syndrome or Foville syndrome).
General symptoms of stroke in Pontine branches of medulla
Medulla: locked-in syndrome
■ Bilateral damage usually occurs → locked-in syndrome
■ Paralysis, unable to talk, some facial and eye movements are preserved
■ Spinothalamic sensation is retained
■ Loss of discriminatory sensation in the limbs
General symptoms of stroke in Pontine branches - lacunar infarction
- Occlusion of deep penetrating arteries → subcortical infarction with preservation of cortical function (language, other cognitive and visual functions)
- Pure motor hemiplegia
- Pure sensory stroke
- Dysarthria/clumsy hands
- Ataxic hemiparesis
- Severe dysarthria with facial weakness
Lacunar infarction- Clinical manifestation of Pure motor hemiplegia
- which vessel affected?
- equal weakness of contralateral face, arm and leg
- with dysarthria
● Vessel: lenticulostriate artery
Lacunar infarction- Clinical manifestation of Pure sensory stroke
- which vessel affected?
Clinical:
* numbness and tingling of contralateral face and limbs,
* sensory examination may be normal
● Vessel: thalamogeniculate artery
Lacunar infarction- Clinical manifestation of Dysarthria/clumsy hands
- which vessel affected?
● Clinical:
* dysarthria due to weakness of ipsilateral face and tongue
* associated with clumsy but strong contralateral arm
● Vessel: perforating branch of basilar artery
Lacunar infarction- Clinical manifestation of Ataxic hemiparesis
- which vessel affected?
- mild hemiparesis with more marked ipsilateral limb ataxia
● Vessel: perforating branch of basilar artery
Lacunar infarction- Clinical manifestation of Severe dysarthria with facial weakness
- which vessel affected?
Clinical:
* dysarthria,
* dysphagia,
* mutism can occur with mild facial and no limb weakness
● Vessel: lenticulostriate artery
lenticulostriate artery Lacunar infarction can cause what symptoms?
- Pure motor hemiplegia
- Severe dysarthria with facial weakness
Lacunar infarction in thalamogeniculate artery can cause what symptoms?
Pure sensory stroke
Lacunar infarction in perforating branch of basilar artery can cause what symptoms?
- Dysarthria/clumsy hands
- Ataxic hemiparesis
General symptoms of stroke in Superior cerebellar artery
○ Cerebellum:
disturbed gait, limb ataxia
○ Brain stem:
ipsilateral Horner’s syndrome,
contralateral sensory loss,
pain, temperature
(including face)
Horner syndrome
(Oculosympathetic paresis)
- neurological disorder
- characterized by a symptom triad of :
1. miosis (an abnormally small pupil),
2. partial ptosis (drooping of the upper eyelid),
3. and facial anhidrosis (absence of sweating). - This condition results from lesions that interrupt the ipsilateral sympathetic nervous supply to the head, eye, and neck.
Horner syndrome
(Oculosympathetic paresis) causes
- Most cases of HS are idiopathic
- brainstem stroke
- carotid dissection
- neoplasm
This condition results from lesions that interrupt the ipsilateral sympathetic nervous supply to the head, eye, and neck.
General symptoms of stroke in AICA
○ Cerebellum: ipsilateral limb ataxia
○ Brain stem:
ipsilateral Horner’s syndrome, ipsilateral sensory loss (pain and temperature of face),
ipsilateral facial weakness,
ipsilateral paralysis of lateral gaze,
contralateral sensory loss (pain,
temperature of limbs of trunk)
General symptoms of stroke in PICA
○ Cerebellum:
dysarthria,
ipsilateral limb ataxia,
vertigo,
nystagmus
○ Brain stem:
ipsilateral Horner’s,
ipsilateral facial sensory loss, ipsilateral pharyngeal and
laryngeal paralysis (dysphagia),
contralateral limb impairment of pain and temperature sensation
what is Wallenberg syndrome (WS)
is a neurological disorder that is due to damage to the lateral portion of the medulla oblongata (i.e., the lateral medullary syndrome).
WS is typically due to ischemia from a vertebral artery or posterior inferior cerebellar artery infarction.
- Depends only on the blood supply from the vertebral
arteries
○ Wallenberg syndrome may manifest if both vertebral arteries are
occluded
General symptoms of stroke in Anterior spinal artery
○ Causes medial medullary infarct
○ Contralateral hemiparesis (facial sparing),
contralateral impaired proprioception and vibration,
ipsilateral tongue weakness
list Alternating syndromes
● Superior alternating hemiplegia/syndrome (Weber’s syndrome)
● Middle alternating hemiplegia (Foville syndrome)
● Inferior alternating hemiplegia (Medial medullary syndrome)
where is the lesion in● Middle alternating hemiplegia (Foville syndrome)
○ Lesion in caudal and medial pons
Middle alternating hemiplegia (Foville syndrome) symptoms
○ Ipsilateral horizontal gaze palsy (CN VI),
* CN VII palsy,
* contralateral hemiparesis,
* hemisensory loss,
* internuclear ophthalmoplegia
