A 52-year-old man had gone for quick nap after watching an exciting football match on the television. When his wife tried to wake him she found that he was confused, unable to speak clearly with a pronounced slurring of his words. On trying to get out of bed he was unsteady on his feet and stumbled several times on the way to the bathroom. He found that the weakness particularly affected the right side of his body. He became very anxious which was heightened by the fact that he reported seeing everything in double. At this point his wife became very concerned and phoned the emergency services who arrived within 10min as the couple live close to a major teaching hospital.

On examination the following were identified: Right side hemiparesis and with reduced pinprick and two-point discrimination on the right side of his head and arm. Brisk deep tendon reflexes on the right and a positive Babinski reflex on the right. Difficulty in answering questions but he seemed to have good understanding of what was said to him.. It is confirmed that he has suffered a stroke.

? Corticospinal tract Extrapyramidal tracts Sensory pathways Diagnostics Aphasias Neglect and extinction Thrombolysis Anxiolytics/ depression

Aphasias Language most dominant in left hemisphere After stroke compensation by right hemisphere a partial or complete loss of language skills resulting from an organic cause 40% of stroke patients Primary vs. Secondary aphasias Primary- a problem with the language processing itself Secondary- results from memory impairment, perception, or attention disorders

BrocaWernicke Inferior frontal gyrusPosterior regions of superior temporal gyrus. (Angular gyrus) Brodmann’s Area 44 & 45Brodmann’s Area 22 Speech production, articulationMeanings, auditory codes Expressive, Non-fluent aphasia- impaired speech production Fluent, receptive aphasia- speak nonsense! +deficits in comprehension Primary aphasia Middle cerebral artery Superior Sagittal sinus Middle cerebral artery Double dissociation- 2 distinct areas control speech comprehension and production

Broca’s Aphasia Speech described as: telegraphic- unessential words left out anomia- difficult labelling objects aggramatism- can’t process gramatically complex sentences

Diagnostic methods

MRI Magnetic resonance imaging Relies on the medium of water, abundance of protons. Ischaemic stroke- cerebral oedema in area of infarct Haemorrhagic stroke- blood

Electromagnet applies a strong magnetic field to the hydrogen atoms in water molecules (1.5-3T) Aligns them all into 1 plane Radio waves then cause the protons to spin, emitting a signal which is picked up by a receiver. Different concentrations of nuclei show up as different intensities

Detects oedema associated with stroke and enables non-invasive monitoring Can measure size, shape and density MRI Limitations high cost long scanning duration decreased sensitivity in the detection of subarachnoid haemorrhages

fMRI Measures changes in cerebral blood flow (haemodynamic response) during cognitive tasks Oxygenated: deoxygenated blood ratio (BOLD contrast) Oxygen-rich blood flow increases in areas of increased activity Indirect way of measuring activity

Advantages High spatial resolution: 3 mm (> High Field) Better time resolution: each volume 2-3s Non-invasive Disadvantages hemodynamic response is slow (12-15 s) an indirect measure of neural activity only shows where lesion/activity is and not how mechanisms function Uses statistical procedures to extract underlying signal

Neglect and Extinction Attention disorder Lesion to parietal lobes (can be frontal) NB. More common in lesions to R hemisphere! Representational Model, Attentional Bias model Neglect syndrome: Unawareness of side/space opposite to lesion Extinction: mild form of neglect, only on double stimulation: ipsilateral and contralateral to lesion Diagnosed by line cancellation, visual fields

Exam Technique