Neurology localization

Neuro-localization is

A systematic process of identifying the location of nervous system lesion

• Based on information obtained by the neuro exam

- Utilizes what we know to be true of the nervous system

Clinical signs of nervous system lesions are LOCATION based, not disease based

• A tumor, stroke, or infection in the same area of the brain will ALL cause the same clinical signs

-Can have one, few, or all of the clinical signs listed

Areas of neuro-localization:

• Intracranial: Forebrain, Cerebellum, Brainstem, Vestibular System

• Spinal Cord: C1-C5, C6-T2, T3-L3, L4-53

- Neuromuscular: Peripheral Nerve, Neuromuscular junction, Muscle

Forebrain function is :

Learning, thinking, behavior, emotion, sensory processing, initiates voluntary movement (Remember, there is a nervous system "crossover" at the forebrain, so the RIGHT side of the forebrain controls the LEFT side of the body...this ONLY applies to the forebrain)

Clinical Signs of Forebrain Disease:

Altered mentation - awake but not alert, dull/sleepy

• Behavior Changes

• Seizures

• Head Pressing

• Hemi-Neglect (failure to recognize half of their body/world)
  Gait/Posture: Circling (toward lesion), compulsive walking, head turn

• Exam deficits: Menace, nasal stimulation, proprioception

Cerebellar Function is :

Coordination of movement: rate, range, fluidity

Clinical Signs of Cerebellar Disease:

• Gait/Posture: Wide stance, Swaying, Hypermetric gait, cerebellar ataxia

• Exam deficits: Menace

Brainstem Function is:

Regulation of sleep/wake cycles and autonomic functions (HR, BP, RR, etc etc)

Clinical Signs of Brainstem Disease:

• Inappropriate alertness, poor level of consciousness

• Inappropriate vital signs

• Gait/Posture: leaning/falling, tight circling, head tilt, vestibular ataxia

• Exam deficits: Menace, nasal stimulation, PLR, palpebral, physiologic nystagmus, gag reflex, proprioception, development of abnormal nystagmus or strabismus

Vestibular System Function is:

Balance including rotation and acceleration/deceleration. Comprised of semicircular canals, vestibulocochlear nerve, brainstem, and cerebellum working together.

(If they ONLY have these signs, we can't be more specific)

Clinical Signs of Vestibular Disease:

• Gait/Posture: Leaning/falling, head tilt, wide stance, vestibular ataxia

• Exam deficits: proprioception, development of abnormal nystagmus or strabismus, palpebral

Spinal Cord Function is:

Ability to walk and stand, strength against gravity, bladder coordination, respiratory muscles, transmits information from the body to the brain and vice versa

Clinical signs of Upper Motor Neuron Segment Disease (C1-C5 or T3-L3)

• Gait/Posture: Proprioceptive ataxia, paresis, plegia (para- or tetra-)

• Exam deficits: proprioception, spinal pain, cutaneous trunci, loss of pain sensation in limbs, loss of bladder function, increased muscle tone

Clinical signs of Lower Motor Neuron Segment Disease (C6-T2 or L4-S3)

• Gait/Posture: Proprioceptive ataxia, paresis, plegia (para- or tetra-)

- Exam deficits: proprioception, myotatic reflexes in affected limbs, perineal reflex, spinal pain, loss of pain sensation in limbs, loss of bladder function, decreased muscle tone

Neuromuscular System Function is:

Ability to walk and stand, strength against gravity, bladder contraction, respiratory muscles, development of sensory information or production of motor function

Neuromuscular is a "catch-all" for many diseases that don't all appear clinically similar. These types of diseases can be difficult or impossible to definitively diagnose

Three types of neuromuscular disease:

Neuropathy - Failure of peripheral nerve conduction

Junctionopathy - Failure of neurotransmitters between nerve and muscle

Myopathy - Failure of muscle to carry out nerve impulses

Clinical Signs of Neuromuscular System Disease:

• Posture/Gait: diffuse weakness, paresis or plegia (para- or tetra-)

• Exam deficits: diffuse myotatic reflexes, cranial nerve reflexes, perineal reflex, cutaneous trunci reflex