Neurosurgery

The 10% Brain Myth

A common but false belief that humans only use 10% of their brain. Scientific consensus is that all areas are utilized.

Neurological Surgery

A medical and surgical specialty treating conditions of the central nervous system (CNS) and its supportive structures, including the brain, pituitary gland, spinal cord, and peripheral nervous system.

Central Nervous System (CNS) Healing Capacity

The brain has limited healing capacity, typically not regenerating new neurons, but primarily heals through neuroplasticity and reallocation of redundant pathways.

Primary Injury (CNS)

Direct impact from a pathological process on the central nervous system.

Secondary Injury (CNS)

Effects following a primary injury, which can cause further damage (e.g., hypoxia/ischemia, cerebral edema).

Cerebrospinal Fluid (CSF)

Represents 10% of intracranial volume and acts as a primary compensatory mechanism for intracranial pressure (ICP), with adults having 130-150 mL and a daily production of ~500 mL.

Monro-Kellie Doctrine

States that the skull is a fixed space; if one intracranial component (blood, CSF, or brain) increases, others must decrease, or intracranial pressure (ICP) will rise.

Raised Intracranial Pressure (ICP) Symptoms

Headache, vomiting, lethargy/stupor, and irritability.

Cushing’s Triad

Indicators of raised intracranial pressure, characterized by hypertension, bradycardia, and abnormal respiration patterns.

Glasgow Coma Scale (GCS)

A tool for assessing head injury, evaluating eye opening, motor function, and verbal response, with scores ranging from 3 (unresponsive) to 15 (fully alert). A decrease by 2 points is significant.

Epidural Hematoma

A medical emergency located between the skull and dura mater, typically associated with arterial injury (e.g., middle meningeal artery), often presenting with a lucid interval followed by rapid decline.

Subdural Hematoma

Located immediately under the dura mater, resulting from tearing bridging veins, classified as acute, subacute, or chronic based on the time frame post-injury.

Intracerebral Hematoma

A space-occupying lesion within the brain that typically does not require intervention unless significant edema arises.

Hydrocephalus

A congenital condition requiring medical and/or surgical intervention (e.g., ventricular shunt, endoscopic third ventriculostomy) due to abnormal CSF accumulation.

Hydranencephaly

A congenital condition characterized by a lack of brain development where the cerebrum is absent, but the brainstem and cerebellum are present, usually detected between 6-18 months of age.

Neural Tube Defects

Congenital conditions like Anencephaly, Encephalocele, and Spina Bifida, related to genetic factors and folate deficiency.

Craniosynostosis

A congenital condition involving the early fusion of cranial sutures, most commonly the sagittal suture, requiring surgical corrections like vault reconstruction.

Neurosurgical Residency

A 7-year training program in neurological surgery requiring 1+ years of research, along with additional training in neurology, neuropathology, neuroradiology, and neurocritical care.

Subdural Empyema

An infection that spreads through venous pathways from sinusitis or otitis, requiring urgent surgical washout and antibiotic therapy.

Cerebral Abscess

Often secondary to infections (e.g., endocarditis, sinusitis), which may require drainage if its size exceeds 3 cm or if it is adjacent to ventricles.

Medically Intractable Seizures

Seizures that do not respond sufficiently to medication and may warrant surgical options such as anterior temporal lobectomy, hemispherotomy, or corpus callosotomy.

Endovascular Surgery

An operative management technique used in neurological surgery, involving minimally invasive procedures performed inside blood vessels to treat conditions affecting the nervous system.