Neurological Emergencies - part 1 ppsx

Neurological Emergencies Fourth edition [...]... these tests are negative, however, then the neck stiffness alone is more suggestive of a foraminal pressure cone .15 Fundal examination The presence of papilloedema or fundal haemorrhage or emboli, together with the findings of hypertensive vascular or 11 NEUROLOGICAL EMERGENCIES Table 1. 1 Neurological assessment of coma Function Response/reaction Glasgow Coma Scale Eye opening Motor response Verbal... to 6 MEDICAL COMA bilateral frontal lobe lesions, diffuse cortical lesions, or lesions of the deep grey matter .11 8 The locked-in syndrome Feldman12 described a deefferented state caused by a bilateral ventral pontine lesion involving damage to the cortico-spinal, cortico-pontine, and cortico-bulbar tracts The patient has total paralysis below the level of the third nerve nuclei and, although able to... limbs and asymmetry of reflexes will help to support this possibility Focal seizures are an important indicator for a focal cause for the coma, and the observation of more generalised 17 NEUROLOGICAL EMERGENCIES Box 1. 1 Clinico-anatomical correlation in coma Bilateral hemisphere damage Symmetrical signs Fits or myoclonus Normal brain stem reflexes Normal oculocephalic and oculovestibular responses Normal... intracranial pressure Neurological examination The position, posture and spontaneous movements of the unconscious patient should be noted A formal neurological examination consists of the elicitation of various reflex responses14; the most important aspects are those that define the level of consciousness, identify the activity of the brain stem, and search for evidence of lateralisation (Table 1. 1) Level of... suggests uncal 13 NEUROLOGICAL EMERGENCIES herniation or a posterior communicating artery aneurysm Midbrain lesions typically cause loss of the light reflex with mid-position pupils, whereas pontine lesions cause miosis but a retained light response Fixed dilatation of the pupils is an indication of central diencephalic herniation and may be differentiated from the fixed dilatation due to atropine-like agents... cannot be mimicked and their 14 MEDICAL COMA Midbrain Mid position fixed Tectal Large fixed Pontine Pinpoint Diencephalic Small reactive Third nerve Fixed dilated ptosed Figure 1. 3 Pupillary changes presence excludes psychogenic unresponsiveness .14 Periodic alternating gaze or “ping-pong” gaze is a repetitive conjugate horizontal ocular deviation of uncertain aetiology .17 Spontaneous nystagmus is rare... but is not common In patients with pontine depression the 15 NEUROLOGICAL EMERGENCIES (a) 0° C (b) 0° C 0° C (c) (d) Figure 1. 4 Reflex eye movements (a) Normal doll’s eye; (b) tonic oculovestibular response; (c) dysconjugate oculovestibular response; (d) absent oculovestibular response oculocephalic response is lost and the eyes remain in the mid-position of the head when turned The oculovestibular response... on the latest evidence The first-time reader will find succinct reviews of the pathogenesis and especially management of all the common neurological emergencies Neurological is used in the broadest sense to include neurosurgery (head injury, compression, subarachnoid haemorrhage, raised intracranial pressure), psychiatry (delirium, acute behaviour disturbances), neuro-ophthalmology (acute visual failure),... possibility of a metabolic or ischaemic-anoxic cause for coma with diffuse cortical irritation The testing of tone as part of the assessment of muscle function can be useful in the comatose patient where it is possible to detect asymmetry of tone, not only in the limbs but also in the face There are recognisable patterns of signs associated with the site of pathology (Box 1. 1). 21 By this stage it should be possible... follows hypoxic-ischaemic insult only 11 % will make such a recovery; of those in coma due to cerebrovascular disease only 7% can be expected to make such a recovery Twenty per cent of patients in coma following a hypoxic-ischaemic injury will enter the vegetative state due to the likelihood of hypoxic ischaemia resulting in bihemispheric damage with relative sparing of the brain stem Apart from the . Neurological Emergencies Fourth edition