Traumatic Brain Injury
TBI can be divided into Primary and Secondary Brain Injuries. Primary injury refers to the “initial blow” or the immediate injuries following the event whereas the Secondary injury refers to the physiological responses that ensue from the Primary injury.
Primary Injuries can be further divided into Focal and Diffuse injuries
Epidural hematomas: Lateral Skull Fractures with tearing of middle meningeal artery and vein often leading to involvement of the temporal and temporoparietal regions. Usually a period of initial loss of consciousness followed by a lucid period and finally a period of neurological decline. SURGICAL EVACUATION is often needed.
Subdural hematomas: More common than epidural hematomas. Caused by tearing of bridging vein between cortex and venous sinus and accumulation of blood in the subdural space. The underlying brain injury usually determines outcome in 80% of cases. SURGICAL EVACUATION is often needed.
Cerebral Contusions: Initial period of loss of consciousness followed by slow recovery period with intermittent fluctuations in consciousness, seizures, and focal neurological deficits from the edema that develops. Usually NO SURGERY in these cases.
Pathogenesis: Edema and/or intracranial bleeding leads to increased intracranial pressure and subsequent compression and deformation of brain tissue. Inflammatory mediators (e.g. cytokines), neurotoxic neuropeptides, and glutamate toxicity likely contribute to the damage of surrounding brain tissue. Some experts believe the secondary response is more damaging than the primary response as inflammation and edema are damaging to brain tissue.
Clinical Signs and Symptoms of TBI
- Also called “Post Concussive Syndrome”
- Cognitive disturbances (may mimic symptoms of schizophrenia)
- Disordered Sleep
- Anxiety/Anxiety Disorders (GAD, PTSD, OCD, Panic Disorder)
- Depression (most common)
- Affective Lability
- Personality Changes
- Apathy/lack of spontaneity
- Psychosis (rare, usually seen with frontal and temporal lobe injuries and seizures)
- Mania (rare)
Management of Traumatic Brain Injury (TBI)
Patients with TBI are more sensitive to medication side effects (e.g., extrapyramidal side effects, sedation, orthostasis, etc.). Therefore, patients are started on medications at much lower doses and titrated much more slowly.
- Typical antipsychotics (EPS risk)
- Clozapine (seizure risk, sedation, cognitive impairment)
- Benzodiazepines (delirium risk, falls, cognitive impairment, paradoxical disinhibition)
- Barbiturates (delirium risk, falls, cognitive impairment, paradoxical disinhibition)
- Anticholinergics (delirium risk)
- Antihistamines (delirium risk)
- Alpha-1 blockers (falls, orthostasis)
- Selective Serotonin Reuptake Inhibitors (Citalopram, Fluoxetine, Sertraline): For depression, anxiety, irritability, and agitation
- Propranolol: For aggression
- Amantadine: For cognitive impairment/Executive dysfunction
- Modafinil/Armodafinil: For cognitive impairment/Executive dysfunction
- Psychostimulants (Methylphenidate, Amphetamines): for depression, apathy, fatigue, cognitive deficits
- Buspirone: for depression, anxiety, irritability, and aggression
- Electroconvulsive Therapy (ECT): Except in patients with mass occupying lesions
- Valproic acid: For Mania, Aggression, Irritability, Anxiety, Agitation
- Carbamazepine: For Mania, Aggression, Irritability, Anxiety, Agitation
- Atypical (2nd generation) Antipsychotics: Try to avoid agents that lower the seizure threshold (e.g., clozapine, Olanzapine)
- Lithium: Controversial. Some data suggests neurotoxicity, others demonstrate neuro-protection. If seizure history, try to avoid.
- Levenson, J. L. (2019). The American Psychiatric Association Publishing textbook of psychosomatic medicine and consultation-liaison psychiatry. Washington, D.C.: American Psychiatric Association Publishing.
- Stern, T. A., Freudenreich, O., Fricchione, G., Rosenbaum, J. F., & Smith, F. A. (2018). Massachusetts General Hospital handbook of general hospital psychiatry. Edinburgh: Elsevier.
- J. Ferrando, J. L. Levenson, & J. A. Owen (Eds.), Clinical manual of psychopharmacology in the medically ill(pp. 3-38). Arlington, VA, US: American Psychiatric Publishing, Inc.
- Schatzberg, A. F., & DeBattista, C. (2015). Manual of clinical psychopharmacology. Washington, DC: American Psychiatric Publishing.
- Arciniegas, Yudofsky, Hales (editors). The American Psychiatric Association Publishing Textbook Of Neuropsychiatry And Clinical Neurosciences. Sixth Edition.
- Schatzberg, A. F., & Nemeroff, C. B. (2017). The American Psychiatric Association Publishing textbook of psychopharmacology. Arlington, VA: American Psychiatric Association Publishing.
- Mendez, M. F., Clark, D. L., Boutros, N. N. (2018). The Brain and Behavior: An Introduction to Behavioral Neuroanatomy. United States: Cambridge University Press.
- Hales et al. The American Psychiatric Association Publishing Textbook of Psychiatry. Sixth Edition