Akathisia

from the greek meaning without sitting.

is a syndrome characterized by unpleasant sensations of “inner” restlessness that manifests itself with an inability to sit still or remain motionless.

etiology:

• as a side effect of medications:
• neuroleptic antipsychotics eg phenothiazines
• antispasmodics
• antidepressants.
• to a lesser extent, be caused by Parkinson’s disease and Parkinsonian-like syndromes.

Chvostek sign or Weiss sign

 

• One of the signs of tetany seen in hypocalcemia.
• An abnormal reaction to the stimulation of the facial nerve.
• When the facial nerve is tapped at the angle of the jaw (i.e. masseter muscle), the facial muscles on the same side of the face will contract momentarily (typically a twitch of the nose or lips)

Pathophysiology

due to hypocalcaemia (ie from hypoparathyroidism, pseudohypoparathyroidism, hypovitaminosis D) with resultant hyperexcitability of nerves.

Palmar Reflex

a flexion of the fingers caused by stimulation of the palm of the hand. The reflex is present at birth and usually disappears by 6 months of age.

this reflex may reappear in later life due to some pathologic neurologic conditions.

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Mosby’s Medical Dictionary, 8th edition. © 2009, Elsevier.

Tinel’s sign

 a tingling or pins and needles sensation in the distal end of a limb when percussion is made over the site of a divided nerve.

It indicates a partial lesion or the beginning regeneration of the nerve.

Ototoxicity

Having a toxic effect on the structures of the ear, especially on its nerve supply.

Resulting in damage to the ear (oto-), specifically the cochlea or auditory nerve and sometimes the vestibular system, by a toxin.

Infusion of certain medications (eg. Lasix) by IV push at rates higher than recommended may result in ototoxicity.

Facial Nerves

12 Cranial Neuves (Neural Tracts Leaving the Brain)

Vertebral Column, Intervertebral Disks and Nerves of the Body

A bulging disk simply extends outside the space it should normally occupy. The bulge typically affects a large portion of the disk, so it may look a little like a hamburger that’s too big for its bun. Usually bulging is considered part of the normal aging process of the disk and is therefore common to see on MRIs.

A herniated disk, on the other hand, results when a the center of the intervertebral disk (the nucleus pulposus) protruding out through the tough outer layer of cartilage (called the annulus fibrosus).  Herniated disks are also called ruptured disks.

Below CT of Disk Herniation of the L4-L5 intervertebral disk

Brain Tumors

 

Localized intracranial space occupying lesions.

• Tumors usually grow as a spherical mass or diffuse and infiltrate tissue

 

Tumor Effects

• occur from the compression and infiltration of tissue
• increased intracranial pressure
• cerebral edema
• seizure activity
• focal neurologic signs
• hydrocephalus
• altered pituitary function

 

Effects of Neoplasm depend on the region of the brain occupied by the tumor:

Primary tumors: originate from cells and structures within the brain

Secondary (metastatic) tumors: develop from structures outside the brain

• occur in 20-40% of all patients with cancer
• brain tumors rarely metastasize outside the CNS
• metastasis origin

1. lungs
2. breast
3. lower GI tract
4. pancreas
5. kidneys
6. skin

 

Etiology:

Glial and Meningeal tumors: linked to ionizing radiation exposure

Incidence

•  in adults – higher incidence in the fifth, sixth and seventh decades
•  higher incidence in men than women
•  Adult brain tumors originate most often originate from glial cells (forming the supportive structures of the spinal cord and CNS)

MRI of Brain tumor:

Neurotmesis

A type of nerve damage where both the nerve and the nerve sheath are damaged. Only partial recovery may occur.

Multiple Sclerosis and Amyloid Lateral Sclerosis Comparison

 

Feature	Multiple Sclerosis	Amyloid Lateral Sclerosis
Disease	Affects motor and sensory neurons	Affects motor neurons/ Sensory and cognition not affected
Incidence	Higher in women	Higher in men
Genetics	Mutation in the MHC portions of chromosomes on the HLA regions of the genes	Mutation of the SOD1 gene on chromosome 21
Pathophysiology	Neural demylination and Death of oligodenrocytes producing myelin	Superoxide dismutase gene that neutralizes harmful free radicals is mutated
Manifestations Signs and Symptoms	Depends on the region and extent of neural demylination. Paresthesia (burning, tingling sensation) fatigue decreased muscle strength and coordination gait affected visual impairment bowel and bladder dysfunction	Weakness fascication (muscle twitch) muscle atrophy dysphagia dysarthria
Diagnostics	MRI for plaques. Assay for presence of protein in CSF indiciative of: compromised blood brain barrier autoimmune damage occurance inflammatory processes	electromyography