CT Head
DIAGNOSES
Intracranial haemorrhage
- < 6 hours:
hyperacute haemorrhage, significant hypodense component due to unclotted blood. - 6 hours to 3 days:
homogeneously hyperdense, if there is ongoing active bleeding may see the swirl sign - 3 days to 3 weeks:
isodense to cerebral parenchyma - chronic haemorrhage:
hypodense to brain and may looks like CSF
Hypoxic Encephalopathy
- bilateral hypodense areas in the lentiform nuclei (“owls eyes” in the basal ganglia)
Elevated Intracranial Pressure
- effacement of the basal cisterns
- loss of grey-white differentiation
- loss of sulci
- midline shift
- herniation of cerebellar tonsils into foramen magnum
- uncal herniation (shift of brainstem and distortion of adjacent cisterns, dilation of contralateral temporal horn, compression of the posterior cerebral artery as it crosses the tentorium -> posterior cerebral artery territory infarct)
Lacunar infarcts
- small, deep subcortical infarcts less than 1.5cm in size
- usually involve: basal ganglia, thalamus, internal capsule, corona radiate and brainstem
- cortical border zone infarctions between the territories supplied by anterior, middle and posterior cerebral arteries
- internal border zone infarctions between the territory of the penetrating arteries arising form the superficial pial plexus and territories of the deep penetrating arteries arising from the basal cerebral arteries (corona radiate and centrum semiovale adjacent to the lateral ventricles)
- uncal transtentorial herniation: the uncinate process of the temporal lobe herniates into the anterior part of the opening of the tentorium cerebelli.
- central tentorial herniation: there is symmetrical downward movement of the thalamic region through the opening of the tentorium cerebelli
- subfalcine herniation: displacement of the cingulated gyrus under the falx and across the midline.
- foraminal herniation: there is downward herniation of the cerebellar tonsils into the foramen magnum.
Rim contrast enhancing lesions
- abscess
- tumour
- infections (toxoplasmosis)
References and Links
CCC Neurocritical Care Series
Emergencies: Brain Herniation, Eclampsia, Elevated ICP, Status Epilepticus, Status Epilepticus in Paeds
DDx: Acute Non-Traumatic Weakness, Bulbar Dysfunction, Coma, Coma-like Syndromes, Delayed Awakening, Hearing Loss in ICU, ICU acquired Weakness, Post-Op Confusion, Pseudocoma, Pupillary Abnormalities
Neurology: Anti-NMDA Encephalitis, Basilar Artery Occlusion, Central Diabetes Insipidus, Cerebral Oedema, Cerebral Venous Sinus Thrombosis, Cervical (Carotid / Vertebral) Artery Dissections, Delirium, GBS vs CIP, GBS vs MG vs MND, Guillain-Barre Syndrome, Horner’s Syndrome, Hypoxic Brain Injury, Intracerebral Haemorrhage (ICH), Myasthenia Gravis, Non-convulsive Status Epilepticus, Post-Hypoxic Myoclonus, PRES, Stroke Thrombolysis, Transverse Myelitis, Watershed Infarcts, Wernicke’s Encephalopathy
Neurosurgery: Cerebral Salt Wasting, Decompressive Craniectomy, Decompressive Craniectomy for Malignant MCA Syndrome, Intracerebral Haemorrhage (ICH)
— SCI: Anatomy and Syndromes, Acute Traumatic Spinal Cord Injury, C-Spine Assessment, C-Spine Fractures, Spinal Cord Infarction, Syndomes,
— SAH: Acute management, Coiling vs Clipping, Complications, Grading Systems, Literature Summaries, ICU Management, Monitoring, Overview, Prognostication, Vasospasm
— TBI: Assessment, Base of skull fracture, Brain Impact Apnoea, Cerebral Perfusion Pressure (CPP), DI in TBI, Elevated ICP, Limitations of CT, Lund Concept, Management, Moderate Head Injury, Monitoring, Overview, Paediatric TBI, Polyuria incl. CSW, Prognosis, Seizures, Temperature
ID in NeuroCrit. Care: Aseptic Meningitis, Bacterial Meningitis, Botulism, Cryptococcosis, Encephalitis, HSV Encephalitis, Meningococcaemia, Spinal Epidural Abscess
Equipment/Investigations: BIS Monitoring, Codman ICP Monitor, Continuous EEG, CSF Analysis, CT Head, CT Head Interpretation, EEG, Extradural ICP Monitors, External Ventricular Drain (EVD), Evoked Potentials, Jugular Bulb Oxygen Saturation, MRI Head, MRI and the Critically Ill, Train of Four (TOF), Transcranial Doppler
Pharmacology: Desmopressin, Hypertonic Saline, Levetiracetam (Keppra), Mannitol, Midazolam, Sedation in ICU, Thiopentone
MISC: Brainstem Rules of 4, Cognitive Impairment in Critically Ill, Eye Movements in Coma, Examination of the Unconscious Patient, Glasgow Coma Scale (GCS), Hiccoughs, Myopathy vs Neuropathy, Neurology Literature Summaries, NSx Literature Summaries, Occulocephalic and occulovestibular reflexes, Prognosis after Cardiac Arrest, SIADH vs Cerebral Salt Wasting, Sleep in ICU
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC