PATHOPHYSIOLOGY OF MOTOR SYSTEM Flashcards
What happen with a lesion on frontal lobe
Difficulty with executive functions: hard to manage his daily plans, decision-making problem, not organized…etc.
Change in personality and behavior: more aggressive, less compassion, social isolation…etc.
symptom of upper motor lesion
Site of the lesion :
Cortex, brainstem, spinal cord:
Muscle weakness : Yes (plegia)
Muscle tone : increased (spasticity)
Muscle Atrophy: Disuse Atrophy
Fasciculation (muscle twitching): No Fasciculations
Tendon (stretch) reflex: Hyperreflexia
Plantar reflex(Babinski Sign) : Positive Babinski Sign
lower motor neuron lesion symptom
site of lesion: Anterior horn, roots, nerves, neuromuscular junction
muscle weakness: Yes (myopathy)
muscle tone: decreased (hypotonia)
muscle atrhophy: Denervation Atrophy
fasciculation: Fasciculations
tendon reflex: Hyporeflexia
babinski sign: Negative Babinski Sign
what is hyporflexia during LMN lesion
absence or weak leg extension
what is hyperreflexia of UMN lesion
strong extension of the leg
Injury to the primary motor cortex (lesion A) causes a weakness of the
contralateral inferior facial muscles:
Input to inferior facial muscles from the UMN in primary motor cortex is lost.
Injury to corticobulbar tract (lesion B) causes a weakness of the
contralateral inferior facial muscles:
Input to inferior facial muscles from the UMN in primary motor cortex is lost
Injury to the facial motor nucleus or its nerve (lesion C) causes a weakness of
all muscles of facial expression on the same side of the lesion:
input to superior and inferior facial muscles from LMN is lost.
what is aphasia
Aphasia is a disorder in the comprehension and/or expression of language:
what is broca aphasia
loss of the ability to produce language.
also called non-fluent aphasia.
what is wenickes aphasia
difficulty understanding speech
where is the broca area
the posterior inferior frontal gyrus (inferior part of the motor cortex). For that is also called motor aphasia.
broca aphasia is mostly caused by
stroke
what is multiple sclerosis
an immune-mediated inflammatory disease that causes the demyelination of the nerves of central nervous system so the propagation of AP is stop
what is myasthenia gravis
a neuromuscular disease that causes weakness in the muscles (e.g. drooping of eyelids, difficulty swallowing, shortness of breath).
what happen whit myasthenia gravis
Acetylcholine (Ach) receptors blocked (or destroyed) by antibodies (autoimmune disease).
Reduced transmission of Ach in the muscle.
Impaired muscle contraction.
treatment of myasthenia gravis
Cholinesterase inhibitors: inhibit the metabolism of Ach by the cholinesterase enzyme (i.e., keep more Ach in the synaptic cleft), Thus, boost signals between nerves and muscles to improve muscle strength.
treatment of myasthenia gravis
Cholinesterase inhibitors: inhibit the metabolism of Ach by the cholinesterase enzyme (i.e., keep more Ach in the synaptic cleft), Thus, boost signals between nerves and muscles to improve muscle strength.
what is parkinson disease
Degeneration of the substantia nigra’s neurons: i.e. loss of dopaminergic neurons.
Causes: rigidity, tremor and akinesia (i.e. inability to initiate and stop movement).
2nd most common neurodegenerative disease after Alzheimer’s disease.
what is the 2nd most common neurodegenerative disease after Alzheimer’s disease.
parkinson
direct pathway of parkinson disease
the transient inhibition from the caudate/putamen to the globus pallidus internal is diminished (no activation of D1). Thus, the tonic inhibition of the globus pallidus internal on the thalamus is increased, which results in decreased excitation of the motor cortex (i.e. akinesia, difficulty to initia
indirect pathway of parkinson disease
the transient inhibition from the caudate/putamen to the globus pallidus external is increased (no activation of D2). Thus, the tonic inhibition of the globus pallidus external on the sabthalamic nucleus is decreased, which results in increased excitation of the globus pallidus internal. The latter exerts more tonic inhibition of the thalamus, which results in decreased excitation of the motor cortex (i.e. akinesia, difficulty to stop movement).
parkinson treatment option
Dopamine-based medication : L-Dopa (dopamine precursor).
Deep Brain Stimulation:
Insertion of an electrode deep into the brain
Repetitive and regular electrical stimulation.
Targeted structures: subthalamic nucleus, globus pallidus internal.
what is hungtington disease
Degeneration of caudate and putamen neurons. The size of the caudate and putamen is dramatically reduced.
Causes a movement disorder: hyperkinesia
