Neuro Handouts Flashcards
Location of lesion that causes Spasticity
Upper motor neuron or the corticospinal tract
- Increased muscle tone (hypertonia) is rate dependent.
- Tone increases when passive movement is rapid, & decreases when passive movement is slow.
- Tone is also greater at the extremes of the movement arc.
- During rapid passive movement, initial hypertonia may give way suddenly as the limb relaxes
Common causes
of spasticity of upper motor neuron or the corticospinal tract
- Stroke, especially late or chronic stage
Location of lesion that causes Rigidity
Basal Ganglia System
Describe Rigidity
- Increased resistance that persists throughout the movement arc, independent of rate of movement, is called lead-pipe rigidity.
- During flexion & extension of the wrist or forearm, a superimposed ratchet-like jerkiness is called Cogwheel rigidity & can be due to underlying tremor
Common causes of Rigidity
- Parkinsonism
Location of lesion that causes Flaccidity (or Hypotonia)
- Lower motor neuron system at any point from the anterior horn cell to the peripheral nerves, & in cerebellar disease
Describe Flaccidity (or Hypotonia)
- Loss of muscle tone (hypotonia) causes the limb to be loose or floppy.
- The affected limbs may be hyperextensible or even flail-like
- Flaccid muscles are often weak
Common causes of Flaccidity (or Hypotonia)
- Guillain-Barre syndrome; initial phase of spinal cord injury (spinal shock)
- Stoke
Location of lesion that causes Paratonia
- Both hemispheres in the frontal lobes
Describe Paratonia
- Sudden, irregular changes in tone accompany passive range of motion
- Sudden loss of tone that increases the ease of motion is called FACILITATORY paratonia
- Sudden increase in tone making motion more difficult is called OPPOSITIONAL paratonia
Common causes of Paratonia
- Dementia
What are the 3 components of the GCS
- Eye opening
- Motor Response
- Verbal Response
GCS: Eye opening
4 - Spontaneous: eyes open, not necessarily aware
3 - To speech: nonspecific response, not necessarily to command
2 - To pain: pain from sternum/limb/supraorbital pressure
1 - None: even to supraorbital pressure
GCS: Motor response
6 - Obeys commands: follows simple commands
5 - Localizes pain: arm attempts to remove supraorbital/chest pressure
4 - Withdrawal: arm withdraws to pain, shoulder abducts
3 - Flexor response: withdrawal response or assumption of hemiplegic posture
2 - Extension: shoulder adducted & shoulder & forearm internally rotated
1 - None: to any pain; limbs remain flaccid
GCS: Verbal response
5 - Oriented: Converses & is oriented
4 - Confused: converses but confused, disoriented
3 - Inappropriate: intelligible, no sustained sentences
2 - Incomprehensible: moans/groans, no speech
1 - None: no verbalization of any type
Small or Pinpoint Pupils
- Bilaterally small (1-2.5 mm) suggest damage to the sympathetic pathways in the hypothalamus, or metabolic encephalopathy, a diffuse failure or cerebral function that has many causes, including drugs
Pinpoint pupils < 1 mm
- Suggest a hemorrhage in the pons, or the effects of morphine, heroin, or other narcotics
Midposition Fixed Pupils
- Pupils that are in the midposition or slightly dilated (4-6 mm) & are fixed to light
- Suggest structural damage in the midbrain
Bilaterally Large fixed & dilated pupils
- Severe anoxia & its sympathomimetic effects, as seen after cardiac arrest
- May also result from ATROPINE - like agents, phenothiazines, or tricyclic antidepressants
Bilaterally Large reactive pupils
- May be due to cocaine, amphetamine, LSD, or other sympathetic nervous system agonists
One large fixed & dilated pupil
- Warns of herniation of the temporal lobe, causing compression of the oculomotor nerve (CN III) & midbrain
- May also be seen in diabetic patients from infarction of CN III
Cerebral Cortex lesion Motor signs & symptoms
- Chronic contralateral corticospinal - type weakness & spasticity
Cerebral Cortex lesion Sensory signs & symptoms
- Contralateral sensory loss in the face, limbs, and trunk on the same side as the motor deficits
What can cause cerebral cortex motor & sensory deficits
- Cortical stroke
Brainstem lesion motor signs & signs
- Chronic contralateral corticospinal weakness & spasticity plus CN deficits such as diplopia (from weakness of the extraocular muscles) & dysarthria
Brainstem lesion Sensory signs & signs
- Variable depending on the level of brainstem
What can cause Brainstem motor and sensory deficits
- Brainstem stroke
- MS plaque
Spinal cord lesion motor signs & symptoms
- Weakness & spasticity, but often affecting both sides (when cord damage is bilateral), causing paraparesis or quadriparesis depending on the level of injury
Spinal cord lesion sensory signs & symptoms
- Dermatomal sensory deficit on the trunk on one or both sides at the level of the lesion, and sensory loss from tract damage below the level of the lesion
What can cause Spinal cord motor and sensory deficits
- Trauma
- Spinal cord tumor
Subcortical Gray Matter: Basal Ganglia lesion motor signs & symptoms
- Slowness of movement (bradykinesia), rigidity, & tumor
Subcortical Gray Matter: Basal Ganglia lesion sensory signs & symptoms
- Sensation not affected
What can cause Subcortical Gray Matter: Basal Ganglia motor and sensory deficits
- Parkinsonism
Cerebellar lesion motor signs & symptoms
- Hypotonia, ataxia, nystagmus, dysdiadochokinesis, & dysmetria
Cerebellar lesion sensory signs & symptoms
- Sensation not affected
What can cause Cerebellar motor and sensory deficits
- Cerebellar stroke
- Brain tumor
