Neurologic Intensive Care Flashcards

Question

malignant and benign types of EEG in Hypoxic-ischemic brain injury

Answer 1

**Malignant** * complete or near-complete suppression * burst suppression * generalized periodic complexes * low-voltage output pattern (≤10 microvolts) * intermittent or continuous seizures * lack of reaction to stimuli * alpha-theta pattern **Benign** Continuous backround with preserved backround reactivity

Answer 2

In some patients with coma, 8 to 12 Hz activity is seen; this resembles normal alpha rhythm, but extends beyond the posterior cerebral regions and does not react to stimuli. This so-called "alpha coma" is associated with pontine lesions, and has also been described with hypoxic-ischemic encephalopathy following cardiac arrest, traumatic brain injury, and drug overdose. This should not be confused with a normal EEG pattern, which suggests a psychogenic origin for the patient's unresponsiveness.

Answer 3

CT images are usually normal immediately after a cardiac arrest, but by day 3, they often show brain swelling and inversion of the gray-white densities (with the use of quantitative measures) in patients with a poor outcome MRI parameters associated with poor outcome include: * widespread and persistent cortical DWI abnormalities * the combination of cortical and deep gray matter DWI/FLAIR abnormalities and severe global ADC reduction Still, 20%–50% of patients with good outcomes have DWI abnormalities on MRI and some patients have poor outcomes despite a normal MRI

Answer 4

**It is caused by either:** * dysfunction of the reticular activating system above the level of the mid-pons * dysfunction of both cerebral hemispheres **Coma is a transient state.** Patients recover, die, or evolve into a more permanent state of impaired consciousness: **A)** **Persistent vegetative state** – Φυτική κατάσταση describes patients who are completely unconscious but have spontaneous eye opening during cyclical periods of arousal. Such patients often have reflexive vocalizations (sounds but not words), facial expressions, and movements that can be misinterpreted by hopeful observers as reflecting awareness of their internal or external environment Required features of PVS are: * No evidence of awareness of self or environment and no ability to interact with others. * No evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli. * No evidence of language comprehension or expression. * **Sleep-wake cycles** manifested by the presence of intermittent periods of spontaneous eye opening. * Sufficiently preserved hypothalamic and brainstem autonomic function to permit survival with medical and nursing care. * Bowel and bladder incontinence * Some degree of preserved cranial nerve reflexes and spinal reflexes. **B) Minimally conscious state** – Κατάσταση ελάχιστης συνείδησης describes patients with severe alteration in consciousness who nonetheless can be shown to have some degree of preserved awareness of the external world. **They can at least occasionally demonstrate purposeful movements or responses**. These can include following simple commands, making gestural or verbal responses to questions, making intelligible verbalizations, smiling or crying in response to evocative sounds or images, reaching accurately toward the location of an object, or fixating on and pursuing visual stimuli. **C)** **Brain death** is defined as the irreversible cessation of cerebral and brainstem function. There is no respiratory drive, and thus there are no spontaneous breaths regardless of hypercarbia or hypoxemia. There are no responses arising from the brain (including cranial nerve reflexes and motor responses) to stimuli, although **spinal reflexes may persist**.

Answer 5

Carbon monoxide poisoning

Answer 6

Fat embolism

Answer 7

In SAH, hypertensive therapy should be avoided until the culprit aneurysm is secured (clipped or coiled).

Answer 8

**Apneusis:** a respiratory pause at full inspiration and occurs from bilateral pontine lesions. often with pinpoint pupils and likely decerebrate posture. **Cheyne–Stokes respiration:** a pattern of periodic breathing in which hyperpnea alternates with apnea and the depth of breathing increases and decreases gradually. It is seen in patients with forebrain impairment in the setting of intact brainstem respiratory reflexes, but it is also present in patients with severe cardiopulmonary disease. **Hyperventilation** may be seen in metabolic encephalopathies such as in uremia and hepatic encephalopathy, but has also been reported in patients with midbrain lesions. **Ataxic breathing** is an irregular respiratory pattern (gasping respiration) seen with lesions damaging the respiratory rhythm generator in the upper medulla.

Answer 9

**Decorticate rigidity (αποφλοίωση):** * flexion of the upper extremities at the elbows and extension of the lower extremities * associated with hemispheric dysfunction or a lesion above the red nuclei resulting in disinhibition of the red nuclei, with facilitation of the rubrospinal tracts (which are thought to enhance flexor tone in the upper extremities). * seen in lesions involving the forebrain down to the level of the rostral midbrain, and above the red nuclei. **Decerebrate posture (απεγκεφαλισμός):** * extension and hyperpronation of the upper extremities with extension of the lower extremities * caused by a lesion in the brainstem at or below the superior colliculi and the red nuclei, but above the vestibular nuclei. * the vestibular nuclei are intact (Lesions below the vestibular nucleus will abolish a posture response, and are generally associated with flaccid limbs) **Pinpoint pupils** are seen in pontine lesions, below the red nucleus

Neurologic Intensive Care Flashcards

References: Continuum, Neurocritical care 2024 (35 cards)