Chapter 35 _ 36 - Brain_Spinal Cord Injury and Behavior Disorders_default_9ad9206e

Brain Dysfunctions

Overview of Traumatic Brain Injuries (TBIs)

• Definition: Traumatic brain injuries refer to sudden physical damages inflicted on the brain, limiting its functional capabilities. These injuries can affect cognitive, motor, and emotional functions.

• Types:

  • Closed Injury: Characterized by the absence of penetration into the skull. Common examples include concussions, where brain movement within the skull leads to neurological dysfunction.

  • Penetrating Injury: Involves direct penetration into the skull, typically from firearms or sharp objects, resulting in localized damage and a high risk of infection.

• Common Causes:

  • Falls are the leading cause, particularly in the elderly, due to balance issues.

  • Males are statistically more susceptible to TBIs owing to higher engagement in risk-taking behaviors, such as contact sports, and motor vehicle accidents.

Increase in Intracranial Pressure (ICP)

• Definition: Intracranial pressure is a critical parameter reflecting the pressure inside the cranial cavity, which can rise due to various factors following a TBI, such as swelling (cerebral edema).

• Signs and Symptoms of Increased ICP:

  • Decreased level of consciousness, indicating diminished arousal and awareness.

  • Papillary dilation: Enlarged pupils can suggest brain herniation or severe injury.

  • Classic symptoms include headache, nausea, and vomiting, often leading to Cushing's Triad, which encompasses hypertension, bradycardia, and abnormal respiration patterns.

  • A visual representation, such as imaging scans, may show brain compression due to swelling, emphasizing the need for timely intervention.

Level of Consciousness (LOC)

• Definition: LOC is a critical measure of an individual's self-awareness and ability to respond to environmental stimuli. It plays a pivotal role in assessing brain function after a TBI.

• Levels of Consciousness:

  • Alertness: The highest state, capable of engaging with complex tasks.

  • Lethargy: Individuals are drowsy but can be aroused upon gentle stimulation.

  • Stupor: A state where the individual significantly struggles to respond to stimuli, requiring intense stimulation to elicit a response.

  • Coma: A state of profound unresponsiveness, where the person shows no interaction with their environment.

Mechanisms of Traumatic Brain Injuries

• Blunt Trauma: Results from physical contact, such as a fall or a collision, resulting in direct impact injuries to the brain tissue.

• Coup-Contrecoup Injury: A specific type of injury where damage occurs at the site of impact (coup) and the opposite side of the brain (contrecoup) due to acceleration-deceleration forces, often seen in whiplash scenarios.

• Penetrating Injury: Involves direct trauma entering the skull, commonly due to assault or accidents involving sharp objects.

• Blast Injury: Caused by explosions, which can lead to unique trauma patterns, including concussions and other neurological impairments.

Management of ICP

• Techniques for Managing Increased ICP:

  • External drainage of cerebrospinal fluid (CSF) to relieve pressure.

  • Lobectomy: Surgically removing a portion of brain tissue can alleviate pressure in severe cases.

  • Craniectomy: Involves removing a section of the skull to allow the swollen brain to expand, a critical measure in life-threatening situations.

Assessment of TBIs

• Evaluation: Performing a comprehensive neurological assessment is vital, encompassing:

  • Level of consciousness, using the Glasgow Coma Scale (GCS) to gauge responsiveness effectively.

  • Assessing cranial nerve function and motor/sensory responses to determine the extent of injury.

• Diagnosis Tools: Advanced imaging techniques, such as CT scans and MRIs, are essential for identifying bleeding, structural damage, and other complications.

Types of Intracranial Hemorrhages

• Epidural Hematoma: Characterized by blood pooling above the dura mater, often leading to severe headaches and neurological symptoms that may necessitate surgical intervention to relieve pressure.

• Subdural Hematoma: Blood accumulation beneath the dura mater, often presents slowly over days or weeks, and requires careful monitoring and sometimes surgical treatment.

• Subarachnoid Hemorrhage: Occurs either due to trauma or spontaneous ruptures (such as aneurysms) and typically presents with acute, severe headache and potential neurological deterioration, requiring immediate medical attention.

Spinal Cord Injuries (SCI)

• Definition and Classification: Spinal cord injuries represent damage to the spinal cord, resulting in various deficits based on the injury's location.

• Types of Paralysis:

  • Quadriplegia (Tetraplegia): Paralysis affecting all four extremities, often resulting from injuries in the cervical spine.

  • Paraplegia: Paralysis impacting only the lower extremities, commonly due to thoracic or lumbar spinal injuries.

• Assessment: Utilization of dermatome charts and motor assessments help evaluate sensory responses and functional capabilities post-injury.

Assessment Techniques

• Sensation Assessment: Involves testing using pinprick and light touch; graded from 0 (no sensation) to 2 (intact sensation).

• Motor Assessment: Graded using the ASIA scale from 0 (no contraction) to 5 (full strength and motion).

• Neurological Level Assessment: Identifies the lowest level of the spinal cord with intact motor and sensory function, guiding rehabilitation efforts.

ASIA Scale for Spinal Cord Injury

• Classification:

  • A (Complete): No sensory or motor function below the injury site.

  • B (Incomplete): Preserved sensation but no motor function below the injury.

  • C (Incomplete): Some movement below the injury with major muscle groups weak.

  • D (Incomplete): More function preserved; individuals can have more than half of the key muscle functions below the injury.

  • E (Normal): Normal sensory and motor functions.

• Lesion Types: Complete lesions show total loss of function; incomplete lesions indicate varying degrees of preserved function.

Complications and Diagnosis of SCI

• Shock Types:

  • Neurogenic Shock: A severe condition arises from the disruption of the sympathetic nervous system post-injury, leading to hypotension and bradycardia.

  • Spinal Shock: Characterized by a temporary loss of all neurological activity below the level of injury, can be gradual in recovery.

• Diagnosis: Involves imaging studies (CT/MRI) and functional assessments, with treatment options ranging from surgical interventions to rehabilitation therapies.

Behavioral Disorders

• Evaluation and Treatment: Conducting thorough psychiatric evaluations aids in identifying underlying psychological conditions, employing standardized assessments like the Beck Depression Inventory, Geriatric Depression Scale, and Mini Mental Status Exam (MMSE).

• Psychoactive Medications: Used to manage various psychiatric disorders, requiring weeks to achieve effective therapeutic levels.

• Medications Categories:

  • Antidepressants: Primarily focus on treating depression and related disorders. Common types include SSRIs and SNRIs.

  • Stimulants: Medications such as amphetamines are effective in treating ADHD.

  • Antipsychotics: Address symptoms of schizophrenia, bipolar disorder, and severe depression.

  • Mood Stabilizers: Help prevent mood swings in conditions like bipolar disorder.

Common Behavioral Disorders

• Anxiety Disorders: Encompasses a range including generalized anxiety disorder, panic disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD), affecting daily functioning.

• Major Depressive Disorder: Often more prevalent in women, especially those experiencing postpartum or menopausal changes.

• Bipolar Disorder: Characterized by cycles of depression and mania, requiring intricate management strategies.

• Attention Deficit Hyperactivity Disorder (ADHD): Characterized by persistent inattention and hyperactivity/impulsivity; effectively treated with stimulant medications.

Schizophrenia and Neurodegenerative Disorders

• Schizophrenia: Characterized by distortions in thought processes, perceptions, and emotional responsiveness, attributed to dysregulation of neurotransmitters like dopamine and serotonin; treatment often includes antipsychotic medications combined with psychotherapy for comprehensive management.

• Dementia and Delirium:

  • Delirium: A state of acute confusion and cognitive impairment, frequently reversible; common precipitating factors include medication effects and underlying illness.

  • Dementia: Chronic, irreversible cognitive decline due to neurodegenerative diseases, necessitating thorough evaluation and tailored management plans.

Alzheimer's Disease

• Etiology: Though the exact cause remains unclear, it is closely associated with the presence of amyloid plaques and neurofibrillary tangles in the brain.

• Symptoms: Patients experience significant memory loss, pervasive cognitive decline, emotional instability, and declining motor skills over time.

• Risk Factors: Age is the most significant risk factor; familial predispositions, and lifestyle factors such as social engagement, diet, and physical activity play critical roles in the risk reduction for Alzheimer’s Disease.