Neurology - Dizziness and difficulty walking Flashcards
What causes a “high stepping” and a “stamping gait”?
Peripheral neuropathies:
- Motor nerve damage (e.g. deep peroneal nerve): foot drop occurs with a “high stepping gate”
- Sensory (proprioceptive) nerve damage (seen in syphilis and B12 deficiency as well) cause ataxia and sometimes a “stamping gate”
What causes a “waddling gait”?
Muscle diseases causes proximal muscle weakness and a “waddling gait”
Patients have difficulty walking upstairs and reaching upwards
Causes of proximal myopathy include:
- Metabolic (K+, Ca++ excess/ deficiency)
- Alcoholism
- Steroids
- Thyroid disease
- Inherited
- Inflammatory (myositis)
- Myasthenia
What gait abnormality does spinal cord or upper motor neuron damage cause?
Earliest symptom is “easy tripping up” or difficulty waking on rough ground. As a result the legs drag.
Examination shows a narrow based gait and brisk reflexes often with clonus.
The gait is often described as being “stiff” and “spastic scissoring” together of the legs sometimes occurs.
Causes of spasticity:
- Spinal cord disease
- Cervical myelopathy
- MS
- Stroke
What gait abnormality does cerebellar disease cause?
This causes a wide based, staggering gate (termed “ataxic”).
Midline cerebellar lesions may cause gait ataxia with relatively few signs in the limbs
Causes of cerebellar disease:
- Demyelination
- Chronic alcohol abuse
- Inherited
- Post infectious
What is a hemiplegic gait?
This occurs most commonly after a stroke and occurs on the contralateral side to the lesion.
The arm is held in flexion (due to greater weakness of arm extensors) and the leg is held in extension (due to weakness of leg flexors).
When the patient walks, the leg is swung outwards and forwards in a circular motions - a movement called “circumduction”.
What gait abnormality is seen in Parkinson’s disease?
The earliest feature of PD is an asymmetrical loss of arm swing. Later a stopped posture with shuffling footsteps develops.
The gait may be “festinant” which means that there is a tendency to hurrying and turning is slow resulting in instability
What is marche a petit pas?
This is a wide based gate and small steps that occurs in diffuse vascular disease causing a form of lower body parkinsonism
What is gait apraxia?
Gait apraxia means an inability to carry out complex tasks such as walking.
It occurs as a result of damage to the part of the brain that integrates complex motor function. The gait is disordered and the patient is apparently unable to initiate steps, but individual actions - e.g. making cycling motions on a bed - remain intact.
Occurs in a number of cortical diseases - e.g. vascular disease, normal pressure hydrocephalus
What is the differential diagnosis for ataxia?
Ataxia = incoordination of complex movements such as walking in a straight line.
Anatomically, ataxia is caused by 2 things:
- Lesion of the cerebellum (cerebellar ataxia) causing a wide based gait, falling to the side of the lesion. A “kinetic” of intention tremor is usually present.
- Disorders of proprioception (sensory ataxia) caused by polyneuropathies or lesions of the dorsal columns (classically seen in SACD and syphilis) causing a stomping gait
What infectious diseases can cause ataxia?
Parainfectious ataxia is more common in children
- Chickenpox
- Glandular fever
- Mycoplasma
- Psittacosis
- Legionellosis
What is true vertigo?
True vertigo is the sensation that objects in the room or a patient is moving. It is caused by peripheral pathology affecting the inner ear or CN 8, or central pathology affecting the brainstem.
Other symptoms can give a clue as to the cause:
- Tinnitus with deafness suggests an inner ear pathology
- Nausea and vomiting suggest a brainstem disease
- Diplopia suggests brainstem disease
What are the causes of peripheral vertigo?
- BPPV
- Acute vestibular failure
- Meniere’s disease
- Chronic vestibular failure
- Drugs
What is BPPV?
= Benign paroxysmal positional vertigo
This causes recurrent attacks of transient (lasting seconds) sissiness and vertigo associated with changes in head posture - e.g. lying on a pillow at night.
Conventional physical exam is normal.
What is the Dicks-Hallpike manoeuvre?
This tests for BPPV. It is a specific provocation test performed by bringing the patient from a sitting position down onto their back while turning the head briskly to one side.
If positive, there is nystagmus with rotation towards the side of the lesion and the patients symptoms are replicated. It is caused by debris in the semicircular canals and can be treated by Empley’s manoeuvre.
What is acute vestibular failure?
Patients complain of sudden onset nausea, vomiting and severe vertigo. On examination there is nystagmus on lateral gaze and unsteadiness.
There is a good prognosis, and the condition normally disappears after a few weeks. It has a variety of synonyms such as “acute labyrinthitis”. Pathogenesis is unknown.
