CS - Neurological Examination Part 1 Flashcards
What does the term fasciculation mean and describe the physiology underlying it ?
Fasciculation or muscle twitch is a small, local, involuntary muscle contraction and relaxation which may be visible under the skin.
They arise as a result of spontaneous depolarisation of a lower motor neuron (LMN) leading to the synchronous contraction of all the skeletal muscle fibres within a single motor unit.
What are 2 conditions that may cause bilateral wasting of the small muscles of the hands?
Muscular Dystrophy
Amyotrophic lateral sclerosis
Multiple sclerosis
Define muscle tone?
Muscle tone is the amount of tension (or resistance to movement) in muscles. Our muscle tone helps us to hold our bodies upright when we are sitting and standing. Changes in muscle tone are what enable us to move. Muscle tone also contributes to the control, speed and amount of movement we can achieve.
What might cause an increased or decreased tone?
Increased;
- UMN lesion
- Trauma
- Stroke
- Brain tumors
- Toxins
- Multiple sclerosis
- Parkinson’s disease
- Cerebral palsy
Decreased;
LMN lesion or damage to the brain, spinal cord, nerves, or muscles
What is the scoring system used to assess power ?
The MRC scale of muscle strength uses a score of 0 to 5 to grade the power of a particular muscle group in relation to the movement of a single joint.
Revision
Grade Medical Research Council scale for muscle power
0 - No muscle contraction discernable
1 - Flicker of contraction but no movement
2 - Joint movement when effect of gravity eliminated
3 - Movement against gravity but not examiner’s resistance
4 - Movement against resistance is weaker than normal
5 - Normal power
Define the term deep tendon reflex?
A deep tendon reflex is often associated with muscle stretching. Tendon reflex tests are used to determine the integrity of the spinal cord and peripheral nervous system, and they can be used to determine the presence of a neuromuscular disease.
Can you draw a diagram illustrating the physiology behind the knee jerk reflex?
Image
What are the features of upper and lower motor neuron lesions?
Upper MN;
- Pyramidal muscle weakness
(hemipariesis)
- No muscle atrophy
- No fasciculation
- Increased muscle tone (spasticity)
- Increased stretch reflexes
- Abnormal reflexes (Babinski)
Lower MN;
- Muscle weakness (lesion dependant)
- Muscle atrophy
- Fasciculation
- Reduced muscle tone
- Reduced stretch reflexes
Draw a diagram of the dermatomes of the upper limb?
Image
What common disease may result in impaired vibration senses?
Diabetes
What is peripheral neuropathy ?
Peripheral neuropathy develops when nerves in the body’s extremities, such as the hands, feet and arms, are damaged
What is “glove and stocking” pattern?
A glove and stocking pattern of sensory loss suggests an axonal polyneuropathy.
Nerve root lesions cause sensory loss in a dermatomal pattern. Numbness in a single nerve territory suggests trauma or entrapment neuropathy.
What is mononeuritis?
Mononeuritis multiplex (MNM) is a disorder of the nervous system. It can result in severe pain, loss of motor ability, and loss of sensation in at least two separate areas of the body. The areas affected by MNM depend on the underlying cause of the condition.
What are the features of a cerebellar lesion ?
Cerebellar lesions are most often associated with the clinical findings of ataxia, which may affect the limbs, trunk, or even speech (producing a specific type of dysarthria known as scanning speech), dysequilibrium as manifested by a wide-based gait, and muscular hypotonia.
What is extrapyramidal syndrome?
he term “extrapyramidal effects” describes involuntary movements that you cannot control. These side effects are most common when taking antipsychotic medications? When you experience extrapyramidal effects, movements that were once voluntary happen without your control.
(rubrospinal, reticulospinal, tectospinal and vestibulospinal)
What is the most common tremor at rest and on action?
At rest - Parkinson’s
On action - Essential tremor
(tumour ?)
(both sides of the body, but is often noticed more in the dominant hand because it is an action tremor)
What is foot drop and the neurological causes?
Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot. If you have foot drop, the front of your foot might drag on the ground when you walk.
Foot drop usually results from lesions affecting the peripheral neural pathway related to dorsiflexor muscles, especially the peroneal nerve
What is hemiplegia ?
Hemiplegia (sometimes called hemiparesis) is a condition, caused by a brain injury, that results in a varying degree of weakness, stiffness (spasticity) and lack of control in one side of the body
UMN;
- Arm extensors weaker than flexors (flexors stronger)
- Leg flexors weaker than extensors (extensors stronger)
What is paraplegia ?
Paraplegia refers to the loss of movement and sensation in both legs and, sometimes, part of the lower abdomen.