Ataxia
Core Symptoms (3)
1) Difficulty with balance and gait 2) Clumsiness of the hands 3) Dysarthria
Clinical Manifestations of Cerebellar Dysfunction (6)
1) Stance and Gait 2) Limb Coordination 3) Tremor 4) Muscle Tone 5) Speech 6) Ocular Motor Fluctuations
Ataxia
A neurological disorder characterized by clumsiness (lack of coordination) of voluntary movements that is produced by dysfunction of the cerebellum or cerebellar pathways
Recessive Inherited Ataxias
Ataxia is hidden in the genes of both healthy parents and the child can develop the disease only if they inherit the defective gene from both parents (1) X-linked Recessive - due to genetic deficit on the X-chromosome Appears only in males and is carried forward by the females who go unaffected (2) Friedreich Ataxia - most common cause of hereditary ataxia Age of onset - before 20 Clinical features: dysarthria, sensory loss, pyramidal degeneration, cardiomyopathy, and diabetes There is an axon-less peripheral neuropathy
Speech
Cerebellar Dysarthria - characterized by an altered articulation of words and abnormal fluency of speech May be a simple slowing of speech or a slurring and scanning dysarthria where words are broken into syllables
Tremor
Cerebellar tremor is defined as kinetic (intention) tremor
Both sides ataxia
Conditions affecting both sides of the cerbellum or its connections cause imbalance, gait ataxia, right and left extremity lack of coordination, and dysarthria
Symptoms appear suddenly
Could be caused by: Head trauma stroke cardiac or pulmonary arrest infection tumor in cerebellum exposure to certain drugs or toxins
Classification - Sporadic
Degenerative Stroke or Tumor Toxic/Metabolic Autoimmune
Stance and Gait
Difficulties in equilibrium are the first symptoms of most cerebellar syndromes Wide based stance and gait Gait being characterized by staggering, irregularity of steps, and lateral veering
Muscle Tone
Hypotonia is a typical cerebellar sign Hypotonia - a decrease in the normal resistance offered by muscles to passive manipulation
Hemispheric Cerebellar Dysfunction
Involve motor planning and control of fine motor movements
Midline Cerebellar Dysfunction
Involves axial control, including vestibular function, eye movements, and balance and postural stability
Dysarthria
Motor speech disorder manifested as clumsy, slurring, poorly modulated speech
Autoimmune Ataxia
Ms, acute demyelination encephalmyetis, Guillian-Barre syndrome, can all present acutely with ataxia Characterized by symmetrical weakness which usually affects lower limbs first and then rapidly (hours/days) progresses in ascending fashion
Degenerative Ataxia
One prominent cause of progressive ataxia in older adults is multiple system atrophy MSA isa disease of unknown cause characterized by a loss of oligodendroglia and neurons in multiple structures throughout the brains
Dominant Inherited Ataxias
Passed from an affected parent to child, each with having a 50% chance of inheriting the gene abnormality
Symptoms appear gradually
Possible causes include: deficiencies in vitamin E or B12 congenital abnormalities such as cerebellar deformity remote effects of cancer somewhere in the body slow growing tumors exposure to certain drugs or toxins
One sided ataxia
Stroke, tumors, abscesses, and trauma are more likely to affect just one side of the cerebellum and therefore cause one-sided ataxia
Toxic/Metabolic Ataxia
Toxic can be caused by alcohol - acute and chronic (1) Acute effects of alcohol produce the typical 'drunk' motor impairments (true ataxia) (2) Chronic alcohol can lead to irreversible cerebellar damage (vermis and anterior lobe) Metabolic - celiac disease or sprue can lead to ataxia Celiac disease is a gluten sensitive enteropathy (intestinal disease) with malabsorption. Hypoxia, Vitamin B1, B12, E, and Zinc deficiency, hypothyroidism, and hypoglycemia
Stroke or Tumor Ataxia
Vascular lesions, infections, and structural lesions to the cerebellum or cerebellar pathways can lead to ataxia
Etiology
Ataxias present as chronic progressive diseases starting in infancy (early onset) or adulthood (late onset) A few forms of ataxia are present as acute diseases, such as alcoholic ataxias, whereas other forms present as acute recurrent diseases (episodic ataxias)
Classification - Genetic
Due to gene defect or mutation Dominant inherited ataxias Recessive inherited ataxias
Ocular Motor Fluctuations
Fixation instability with involuntary saccades taking the eyes away from the fixation target followed by corrective saccades returning the eyes to the target
Treatment
There is no treatment for ataxia Physical therapy, occupational therapy, and speech therapy
Limb Coordination
Three main abnormalities of voluntary movements: 1) Asynergia - Movements are broken into isolated subsequent steps and lack easiness and smoothness 2) Dysdiadochokinesia - There is an impaired performance of rapidly alternating movements 3) Dysmetria - There is an abnormal excursion in movements and errors in reaching a precise target