Ataxia:

Symptoms:

Poor coordination.
Unsteady walk and a tendency to stumble.
Difficulty with fine motor tasks, such as eating, writing or buttoning a shirt.
Change in speech.
Involuntary back-and-forth eye movements (nystagmus)
Difficulty swallowing.

What is ataxia?

Ataxia is typically defined as the presence of abnormal, uncoordinated movements. This usage describes signs & symptoms without reference to specific diseases. An unsteady, staggering gait is described as an ataxic gait because walking is uncoordinated and appears to be 'not ordered'. Many motor activities may be described as ataxic if they appear to others, or are perceived by patients, as uncoordinated.

Ataxia can also refer to a group of neurological disorders in which motor behavior appears uncoordinated. Walking, speaking clearly, swallowing, writing, reading, and other activities that require fine motor control may be abnormal in patients with ataxia. Ataxia may result from abnormalities in different parts of the nervous system or different parts of the body, such as ataxic movements due to orthopedic injuries or pain from arthritis or muscle injury.

What causes ataxia?

Ataxia may result from abnormalities in different parts of the nervous system, including the central nervous system (brain and spinal cord) and peripheral nervous system (roots and nerves that connect the central nervous system to muscles, skin, and the outside world). When patients experience abnormal walking or uncoordinated use of their hands or arms, dysfunction of the cerebellum is often responsible. The cerebellum is a rounded structure attached to the brainstem with a central portion (vermis) and two lateral lobes (cerebellar hemispheres). It sits beneath the back of the cerebral hemispheres (occipital cortices). The outer surface of the cerebellum is a continuous layer of nerve cells called the cerebellar cortex. The cortex is a three-layered sheet of neurons that are extensively interconnected and have a highly regular geometric organization. The cerebellar cortex receives information from most parts of the body and from many other regions of the brain. The cerebellum integrates this information and sends signals back to the rest of the brain that enable accurate and well-coordinated movements.

Although unsteady gait may result from problems in different parts of the nervous system or of the body, abnormal walking due to cerebellar dysfunction has distinct features that are usually recognizable. Persons with an ataxic gait due to cerebellar dysfunction keep their legs further apart than normal, referred to clinically as a 'broadened base'. They often stagger and resemble persons who have ingested excessive alcohol. The resemblance of ataxia to inebriation is not a coincidence as alcohol is known to affect the main nerve cells in the cerebellum. Although brief alcohol-induced staggering is usually reversible, repeated exposure to high doses of alcohol may cause degeneration of neurons in the cerebellum and result in persistent ataxia. A main group of cerebellar neurons is unusually susceptible to different forms of injury, including other toxins, prolonged seizures, and lack of oxygen. Cerebellar ataxia differs from gait problems due to abnormalities in other parts of the nervous system, such as the abnormal gait seen in Parkinson's disease, normal pressure hydrocephalus, or different forms of spasticity in the legs. Cerebellar ataxia is also distinguishable from abnormal walking due to pain and/or muscle or orthopedic abnormalities in the hips, legs, or feet.

(For Bambi, it's an abnormality in her legs which makes it so she can't walk)

There are many different types of ataxia. The symptoms and their reason for developing determine the classification. Knowing the type can help doctors evaluate the condition and define a treatment plan.

Bambi's Type:

Friedreich's ataxia: In addition to worsening movement problems, people with Friedreich's ataxia experience stiff muscles and gradually lose strength and feeling in their arms and legs. People with this type of ataxia often also have a heart condition that weakens the heart muscle (hypertrophic cardiomyopathy). Friedreich's ataxia is the most common type of genetic ataxia. It typically develops between ages 5 and 15.

Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is a disease that affects the heart muscle, causing the muscle to enlarge, or "hypertrophy."

At Cleveland Clinic's Miller Family Heart, Vascular & Thoracic Institute, we have a special interest in treating Hypertrophic Cardiomyopathy (HCM). Since 1978, we have treated hundreds of patients and the numbers are increasing each year.

What is hypertrophic cardiomyopathy (HCM)?

Hypertrophic cardiomyopathy (HCM) is a complex type of heart disease that affects the heart muscle. It causes thickening of the heart muscle (especially the ventricles, or lower heart chambers), left ventricular stiffness, mitral valve changes and cellular changes.

Thickening of the heart muscle (myocardium) occurs most commonly at the septum. The septum is the muscular wall that separates the left and right side of the heart. Problems occur when the septum between the heart's lower chambers, or ventricles, is thickened. The thickened septum may cause a narrowing that can block or reduce the blood flow from the left ventricle to the aorta - a condition called "outflow tract obstruction." The ventricles must pump harder to overcome the narrowing or blockage. This type of hypertrophic cardiomyopathy may be called hypertrophic obstructive cardiomyopathy (HOCM).

HCM also may cause thickening in other parts of the heart muscle, such as the bottom of the heart called the apex, right ventricle, or throughout the entire left ventricle.

Normal Heart

Stiffness in the left ventricle occurs as a result of cellular changes that occur in the heart muscle when it thickens. The left ventricle is unable to relax normally and fill with blood. Since there is less blood at the end of filling, there is less oxygen-rich blood pumped to the organs and muscles. The stiffness in the left ventricle causes pressure to increase inside the heart and may lead to the symptoms described below.

Mitral valve changes: The narrowing of the left ventricular outflow tract disrupts the proper function of the mitral valve, resulting in outflow obstruction and increased pressure in the left ventricle.

The obstruction is the result of the mitral valve striking the septum. When this occurs, the mitral valve frequently leaks, causing the blood to go back into the left atrium.

Cellular changes, or changes in the cells of the heart muscle, occur with HCM. Through a microscope, the cells appear disorganized and irregular (called "disarray") instead of being organized and parallel. This disarray may cause changes in the electrical signals traveling through the lower chambers of the heart and lead to ventricular arrhythmia (a type of abnormal heart rhythm).

Disorganized Pattern:

Normal Cell Pattern:

What causes hypertrophic cardiomyopathy (HCM)?

HCM can be inherited, caused by an abnormality in a gene that codes the characteristics for the heart muscle. There are many genes that can cause HCM. When a gene defect is present, the type of HCM that develops varies greatly within the family. In addition, some people who have the HCM gene may never develop the disease.
Hypertrophy may be acquired as a result of high blood pressure or aging.
In other instances, the cause of hypertrophy and HCM is unknown.
Because the cause of HCM varies, it is frequently difficult to identify a high-risk population.