Cerebral Hemispheres Examinations Component What to do/Rationale Indications Disorientation Basics Dysphagia Cognitive decline -> dementia Cannot be performed if the patient has receptive aphasia. Connected with reception and analysis of sensory information. Lesion in the angular gyrus -> distinct clinical syndrome -> Gerstmann’s syndrome. Can only be diagnosed if the patient’s higher centres are intact. A dementia patient would not be able to perform most of these tests. Ask the patient to perform an arithmetical calculation. Take 7s from 100. Inability to do this -> acalculia. Ask the patient to write. Inability -> agraphia Assessment of Dominant Parietal Lobe Function Test for left-right disorientation by asking the patient to show their right arm and then their left arm. If performed correctly -> ask the patient to touch their left ear with the right hand and vice versa. Ask the patient to name their fingers. Inability to do this -> finger agnosia. This agnosia is receptive with defects involving the inability to understand the meaning of stimulations of different types. Mnemonic for these dominant four parietal lobe is AALF: A -> acalculia A -> agraphia L -> left-right disorientation F-> finger agnosia. Needed for processing at higher levels than simple sensations. Rely on an intact simple sensation especially touch and pinprick. Graphesthesia Inability to recognise numbers or letters drawing on the skin. Use a pointy object to do this. Examine for sensory and visual inattention/extinction. One arm is tested at a time and then with both at the same time. Examine for visual fields. A right-sided parietal lesion -> inattention on the left side. A left-sided parietal lesion -> inattention on the right side. Examine for astereognosis. Inability with the eyes closed to recognise object placed in the hand when the ordinary sensory modalities are intact. A parietal lobe lesion -> results in astereognosis on the opposite side. Assessment for Non-Dominant and NonLocalising Parietal Lobe Signs (Cortical Sensation) Examine for two-point discrimination. Involves ability to distinguish a single point from two points closed to each other. The minimal separation that can be distinguished is 3 cm in the hand or foot and 0.6 cm in the fingertips. Ask the patient to shut their eyes and then say whether the points can be distinguished. Examine for dressing and construction apraxia. Dressing apraxia: Patients with non-dominant parietal lobe lesion -> will find it impossible. Constriction apraxia: Ask the patient to copy an image that you have drawn. Examine for spatial neglect: Ask the patient to fill in numbers on an empty clock face. Patients with right parietal lesion -> may only fill in numbers on the left side. The other side is ignored. May also occur in the dominant parietal lobe lesions but less common. Considered with short term and long-term memory. Flower test: Ask the patient to remember a name, an address and the names of three flowers. Ask the patient to repeat them after 5 minutes. Assessment for Temporal Lobe Function Long term memory test Ask things such as: When was World War 2 Memory may be impaired from dementia from any cause. An alert patient with severe memory disturbance may make up stories to fill in gaps in their memory -> confabulation -> typical of Korsakoff psychosis. Causes of dysfunction: Tumours Surgery Stroke Diffuse disease such as: Dementia HIV Emotional, memory, judgement, carelessness about personal habits and disinhibition. Changes to previous personality. May have persistent or alternating irritability and euphoria. Ask the patient to demonstrate a sequence of hand movement -> difficulty in motor planning. Ask the patient to generate as many words as possible beginning with the specific letters -> impairment in verbal fluency. Assess for abstract reasoning. Assessment for Frontal Lobe Function Present an analogy and ask the patient to explain. For example, people in glass houses should not throw stones. Primitive reflexes Grasp reflexes: Place fingers in patients palm -> they should grasp. Assess for resistance and inhibitory control. Ask the patient to do the opposite of what you do. For example, you raise your hand and they depress their hand. Assess for executive functioning. Present a problem solving task and evaluate their ability to organise and strategize. E.g. how would you plan a trip to Dubai?