[10.11b] Surgical Interventions in Neurology (Part 2) V2.pdf

Jose Carlos S. Alcazaren

Who is the doctor that gave the lecture on surgical interventions in neurology?

Surgical treatment of diseases in the brain and spine

What is the definition of neurosurgery?

Neuro-oncology, Infectious, Pediatric, Spine, Trauma, Vascular, and Functional

What are the seven subspecialties of neurosurgery mentioned in the introduction?

Young field

How is the field of neurosurgery described in terms of its age?

Higher mortality and morbidity

Compared to other cutting specialties, what is the risk level of neurosurgical procedures?

Harvey Cushing

Who is the Father of Neurosurgery?

General surgeon

What was Dr. Harvey Cushing's original medical specialty?

Neuro-oncology

Which subspecialty focuses on operating on brain tumors?

Outside the brain parenchyma

What is the definition of an extra-axial tumor?

Inside the brain parenchyma

What is the definition of an intra-axial tumor?

Vestibular schwannoma and meningioma

What are two specific examples of extra-axial tumors given in the figures?

Glioblastoma

What is a specific example of an intra-axial tumor that affects the brain tissue itself?

Pediatric neurosurgery

Which subspecialty deals with diseases in the brain and spine of children?

Myelomeningocele

What is considered the most severe form of spina bifida?

Spine neurosurgery

Which subspecialty focuses on spine tumors, degenerative disorders, and trauma?

Orthopedic surgeons

With which other group of specialists is spine neurosurgery usually shared?

Trauma neurosurgery

Which subspecialty manages brain injuries due to accidents?

Above the dura mater

Where is an epidural hematoma located?

Inside or below the dura mater

Where is a subdural hematoma located?

Chronic subdural hematoma

In which type of hematoma is fluid leveling observed in imaging?

Vascular neurosurgery

Which subspecialty deals with hemorrhages, aneurysms, and malformations?

Third ventricle

In the case of a thalamic hemorrhage, into which structure can the blood bleed?

Surgical clipping and surgical coiling

What are the two treatment options for a large aneurysm?

Detailed history and thorough neurologic exam

What is considered the cornerstone of neurosurgical diagnosis?

Localization of the lesion

What is the primary goal of the neurologic exam according to the scope of neurosurgery?

2 percent

What percentage of the ideal body weight does the brain account for?

50 mL per 100 g of tissue per minute

What is the normal value for cerebral blood flow?

15 percent

What percentage of cardiac output does the brain receive?

120 to 150 cc

What is the total cerebrospinal fluid volume of the ventricular system?

0.3 to 0.4 mL per minute

What is the daily rate of CSF production?

400 to 500 cc

What is the total amount of CSF turned over by the body in one day?

Thrice a day

How many times does the body cycle through its total CSF volume daily?

Monro-Kellie Doctrine

Which doctrine states the brain is in a nonexpandable skull with noncompressible parenchyma and constant blood volume?

CSF and venous blood

According to the Monro-Kellie doctrine, which two volumes decrease first to accommodate a mass?

Basis for almost all neurosurgical interventions

What is the clinical significance of the Monro-Kellie doctrine for neurosurgeons?

Pressure

Neurosurgical interventions are primarily based on taking care of what factor inside the brain?

8 to 15 mmHg

What is the normal range for intracranial pressure in millimeters of mercury?

10 to 20 cm H2O

What is the normal range for intracranial pressure in centimeters of water?

Cerebral Perfusion Pressure

What does the acronym CPP stand for?

CPP equals MAP minus ICP

What is the mathematical formula for calculating CPP?

60 to 80 mmHg

What is the normal range for Cerebral Perfusion Pressure?

Mean Arterial Pressure

What does the acronym MAP stand for?

MAP equals SBP plus 2 times DBP divided by 3

What is the mathematical formula for calculating MAP?

Column of water

How do neurosurgeons practically check pressure when inserting a tube, leading to the use of cm H2O?

1, 2, 3

What is the mnemonic given to remember the MAP formula components?

Cushing's Triad

What set of signs consists of hypertension, bradycardia, and abnormal respiration?

Heart raises blood pressure to maintain CPP

Why does hypertension occur in Cushing's Triad?

Ominous sign

How is the presence of Cushing's Triad described regarding its clinical severity?

Too late

What is Dr. Alcazaren's opinion on the prognosis if all three signs of Cushing's triad are present?

Herniation syndromes

What condition can be caused by prolonged or untreated intracranial pressure?

Subfalcine

Which herniation occurs when the cingulate gyrus moves to the opposite side below the falx?

Distal Anterior Communicating Artery

Which artery can be infarcted during a subfalcine herniation?

Lower extremity hemiplegia

What is the clinical result of an ACA infarct caused by herniation?

Uncal transtentorial

Which herniation occurs when a lateral lesion presses the temporal lobe into the tentorium?

Brainstem and CN III

Which two structures are compressed in an uncal herniation?

Decompression craniotomy

What procedure involves removing the entire skull bone at the area of a hematoma to allow brain movement?

Central transtentorial

Which herniation occurs during a nonlateralizing increase in ICP, such as in hydrocephalus?

Midbrain

Which structure is stuck in the tentorium during central transtentorial herniation?

Tonsillar

Which herniation involves cerebellar tonsils moving into the foramen magnum?

Posterior fossa hematoma

What type of lesion usually causes tonsillar herniation?

Medulla

Compression of which structure in tonsillar herniation causes immediate respiratory failure?

Transcalvarial

Which herniation involves brain tissue moving outward through a penetrating skull lesion or fracture?

Hydrocephalus

What is the term for an abnormal increase of CSF in the ventricles?

Congenital aqueductal stenosis

What is a structural or congenital cause of hydrocephalus?

Communicating and Non-communicating

What are the two main types of hydrocephalus?

Entire ventricular system

In communicating hydrocephalus, what part of the system is enlarged?

Absorption problem

What is the primary pathophysiology of communicating hydrocephalus?

Arachnoid granulations

Which structures fail to reabsorb CSF in communicating hydrocephalus?

TB meningitis and posthemorrhagic scarring

What are two inflammatory causes of communicating hydrocephalus?

Proximal to the obstruction

In non-communicating hydrocephalus, where does the ventricular dilatation occur?

Cerebellar tumor and aqueductal stenosis

What are two specific causes of obstructive hydrocephalus?

Small

How does the 4th ventricle appear in hydrocephalus caused by aqueductal stenosis?

Tonsillar herniation

Which herniation syndrome leads to immediate death due to compression of the medulla?

Cranial MRI with gadolinium contrast

What is the imaging modality of choice for intracranial tumors?

Hydrocephalus

What condition surprisingly did NOT accompany the large cerebellar meningioma in Figure 14?

T2 Scan

Which MRI scan shows a light rim of CSF around extra-axial lesions?

Infiltrative tumors

Which tumors turn grey tissue white and make the brain spongy?

Perilesional edema

What factor aggravates intracranial pressure in the presence of infiltrative high-grade gliomas?

Tissue diagnosis, cytoreduction, and decreasing ICP

What are the three main goals of tumor excision treatment?

Decrease tumor burden

What is the definition of cytoreduction?

Radiotherapy and chemotherapy

What are the common adjuncts to tumor excision surgery?

Ultrasound

Which imaging modality is used for babies with hydrocephalus using the fontanelles as windows?

Slit-like

How do ventricles normally appear on ultrasound, making them hard to see in healthy patients?

Radiation

Why is cranial CT normally not performed on children?

MRI

Which pediatric imaging modality can take 1 to 2 hours, making it difficult for young patients?

Ventriculoperitoneal shunt

What device is used to drain excess CSF in patients with hydrocephalus?

Meningocele, myelomeningocele, and myelocystocele

What are the three types of neural tube defects mentioned?

Folic acid insufficiency

Neural tube defects are highly correlated with what nutritional intake deficiency?

Lower income status

With what socioeconomic status are neural tube defects often associated in the Philippines?

0.4 mg

What is the recommended folic acid dose for women with no known risk factors?

4 mg

What is the recommended folic acid dose for high-risk women who previously had a child with an NTD?

Intracranial abscess

What is a purulent collection within the brain parenchyma?

Cerebritis

What is the initial stage of inflammation before an intracranial abscess forms a capsule?

Contrast MRI

On what imaging does an intracranial abscess appear as a rim-enhancing lesion?

Diffusion restriction

What imaging finding in an abscess is caused by hypercellularity?

Pus

What substance is found inside an intracranial abscess that causes perilesional edema?

Subdural empyema

What is a purulent collection within the subdural space?

Neurosurgical emergency

How is the urgency of a subdural empyema classified?

Seizures

Irritation of the cortical surface by an empyema is often related to what symptom?

Burr hole, craniotomy, and craniectomy

What are the three surgical options for draining a subdural empyema?