See dedicated section: Mental State and Cognitive Assessment.
Core domains include attention, memory, executive function, visuospatial ability, language, and praxis.
Screening tools such as the MMSE or MoCA help detect global impairment; localisation requires more detailed testing.

🗣️ Dysphasia (Aphasia)

Covered under Speech and Language Examination.
Refers to a disorder of language comprehension or production due to dominant hemisphere lesions.

👐 Dyspraxia

🧩 Definition: Inability to perform a learned complex motor task despite normal strength, sensation, coordination, and understanding.
📍 Usually due to left parietal lobe dysfunction but also seen in dementias and diffuse cortical disease.
🧠 Examples of testing:
- “Show me how you would comb your hair.”
- “Strike a match, then blow it out.”
- “Brush your teeth” or “Wave goodbye.”
- Reproduce complex hand shapes such as interlocking fingers or ‘OK’ sign.
🏥 Clinically significant because these deficits impair activities of daily living (ADLs) — frequently identified by occupational therapists during functional assessments.

✍️ Dyslexia and Dysgraphia

📚 Dyslexia: Impaired reading or decoding of written words.
📝 Dysgraphia: Impaired writing and spelling despite preserved motor function.
Both result from dominant parietal (angular gyrus) lesions and commonly accompany dysphasia/aphasia.
They may coexist in degenerative syndromes such as primary progressive aphasia.

🧍 Apraxia

Refers to inability to carry out specific skilled acts despite intact cognition, sensation, and power.
Dressing Apraxia: Puts clothing on incorrectly (e.g. trousers on over the head).
Ideomotor Apraxia: Cannot perform purposeful gestures (e.g. brushing hair) on command — due to dominant parietal injury.
Functionally important because it directly impacts self-care and independence.

🕶️ Agnosia

Inability to recognise or identify objects despite intact sensory function.
Example: unable to identify a £1 coin or a key placed in the hand (astereognosis).
Usually from a contralateral parietal lobe lesion — often right-sided for visuospatial agnosias.

🙈 Anosognosia

Patient lacks awareness of their own neurological deficit.
Common with right parietal or frontal strokes.
Typical scenario: severe left hemiparesis but insists they can walk → high risk of falls.
Clinically important because such patients may refuse treatment or be prematurely discharged if the deficit is not recognised.

👁️ Extinction Phenomenon

When identical stimuli are presented bilaterally (visual or tactile), the patient only perceives the stimulus on the unaffected side.
Suggests a contralateral parietal lobe deficit, classically the right parietal lobe → left sensory neglect.
Bedside test: touch both hands simultaneously — patient reports feeling only one.

📘 Summary Table – Higher Cortical Deficits (Parietal Lobe)

Deficit	Main Feature	Typical Lesion Site	Functional Impact
Dyspraxia	Loss of learned motor skills despite normal motor/sensory function	Dominant parietal lobe	Difficulty performing ADLs
Dyslexia / Dysgraphia	Impaired reading/writing	Angular gyrus (dominant hemisphere)	Communication barriers
Apraxia	Inability to perform specific skilled acts	Dominant parietal lobe	Loss of independence (self-care)
Agnosia	Failure to recognise familiar objects	Contralateral parietal lobe	Difficulty using or identifying tools/objects
Anosognosia	Lack of awareness of own deficit	Right parietal lobe	Risk-taking, unsafe mobility, non-compliance
Extinction	Unilateral sensory neglect with bilateral stimulation	Contralateral parietal lobe	Neglect of left visual/tactile space

📚 References

Ropper & Samuels, Adams & Victor’s Principles of Neurology, 12th ed.
Oxford Textbook of Clinical Neuropsychology (2023).
NICE NG128: Stroke and TIA in Over 16s: Diagnosis and Initial Management.
British Society of Rehabilitation Medicine: Neurorehabilitation Standards (2022).

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Neurological Examination - Cortical Functions

🧠 Cognition