Monday, June 19, 2017

Lacunar infarction notes + mnemonic

Lacunar infarcts are small (0.2 to 15 mm in diameter) noncortical infarcts caused by occlusion of a single penetrating branch of a large cerebral artery.

Pathophysiology:
Lipohyalinosis of the penetrating arteries. (Mnemonic: L for Lipohyalinosis, L for Lacunar)
Microatheroma of the origin of the penetrating arteries.
Lacunar stroke is usually related to a chronic vasculopathy associated with systemic hypertension.

Clinical features:
Penetrating artery occlusions usually cause symptoms that develop over a short period of time, typically minutes to hours. However, a stuttering course may ensue, as with large artery thrombosis, and symptoms sometimes evolve over several days.

As a general rule, lacunar syndromes lack findings such as aphasia, agnosia, neglect, apraxia, or hemianopsia (so-called "cortical" signs). Monoplegia, stupor, coma, loss of consciousness, and seizures also are typically absent.

These syndromes are common :
● Pure motor hemiparesis
● Pure sensory stroke
● Ataxic hemiparesis
● Sensorimotor stroke
● Dysarthria-clumsy hand syndrome

Pure motor hemiparesis: Characterized by weakness involving the face, arm, and leg on one side of the body in the absence of "cortical" signs (aphasia, agnosia, neglect, apraxia, or hemianopsia) or sensory deficit.

Artery / structure involved: Posterior limb of the internal capsule.

Mnemonic: PM - Pure Motor, Posterior limb of internal capsule.

Pure sensory stroke: Numbness of the face, arm, and leg on one side of the body in the absence of motor deficit or "cortical" signs.

Artery / structure involved: Thalamogeniculate branches of the posterior cerebral artery (Ventral posterolateral and ventral posteromedial nuclei)

Mnemonic: MIST
Motor - Internal capsule
Sensory - Thalamus

Ataxic hemiparesis: Ipsilateral weakness and limb ataxia that is out of proportion to the motor deficit. Some patients may exhibit dysarthria, nystagmus, and gait deviation towards the affected side. As with other lacunar syndromes, the above-mentioned "cortical" signs are absent.

Artery / structure involved:  Fibres of the fronto-ponto-cerebellar system in the internal capsule / corona radiata.

Sensorimotor stroke: Characterized by weakness and numbness of the face, arm, and leg on one side of the body in the absence of the aforementioned "cortical" signs.

Artery / structure involved: Sensorimotor strokes arise from infarcts involving the posterolateral thalamus and posterior limb of the internal capsule. The exact vascular anatomy is debated. 

Dysarthria-clumsy hand syndrome: Facial weakness, dysarthria, dysphagia, and slight weakness and clumsiness of one hand are characteristic. There are no sensory deficits or "cortical" signs.

Artery / structure involved: Lacunar infarctions of the anterior limb of the internal capsule, genu of the internal capsule, or corona radiata.

Treatment:
Intravenous alteplase (recombinant tissue-type plasminogen activator or rt-PA) improves outcomes for patients with ischemic stroke in general if administered within 4.5 hours of symptom onset. The available evidence suggests that intravenous thrombolysis is beneficial for patients with lacunar stroke. Most patients with acute ischemic stroke who are not eligible for thrombolytic therapy should be treated with aspirin.

That's all!
-IkaN

4 comments:

  1. Really this group's everday broadcasts are very helpful..thanku admin nd authors

    ReplyDelete
    Replies
    1. Thank you to admin and author, Jaskunwar Singh, without him, I couldn't possibly manage it everyday.

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    2. Always glad to help you in anyway I can.. Love Medicowesome <3

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