2) Respiratory Dysfunction
On assessment, HD persons have been found to have:
Poor lung capacity (VC) and forced expiratory volume (FEV1)
Poor ability to blow – they often force air out in the form of a short ‘huff’
Reduced control of expiration – they tend to exhale by passive relaxation or recoil of the chest and lungs.
Poor cough particularly voluntary cough, and even when choking, cough is poor and unproductive.
Reduced ability to breathe through the nose.
Irregular, uncoordinated breathing pattern. Often inhaling air only when needed, they may gulp or sniff in and may use accessory muscles excessively.
Reduced control of respiratory muscles, often due to involuntary movements.
Abnormal movements in the form of a ‘fluttering’ of the abdominals or a jerkiness of the intercostals may also be observed.
Thus, in practical terms, persons with HD are more susceptible to:
Chest infections. As documented, the greatest cause of death is respiratory failure, pneumonia, etc. Dysphagia contributes to this.
Difficulty with speech, as it requires controlled expiration.
Difficulty with swallowing and eating, as we usually breathe through our nose when doing so.
Difficulty with coughing, because to do so effectively we need to be able to (i) hold breath and (ii) exhale forcefully.
Assessment results indicate that some HD persons may experience disturbance of sensory function – loss of discriminative ability.
Generally the ability to discriminate between the two remains intact. However, there are instances where:
(a) Sensation is dulled e.g., reduced ability to discriminate between, say, hot and very hot.
(b)It takes longer for the information to reach the cortex. The correct response may be given, but the test tube had to be held against the skin for several seconds longer than normal.
4) Sphincter Function
Discriminative ability is generally diminished and becomes more so as the disease progresses
Particularly in latter stage sufferers the ability to localise touch is very poor.
Steroegnosis (the ability to recognise familiar objects by touch with vision occluded):
Overall this was within normal limits in the early stages of the disease. However, in the later stages problems with stereognosis were recognised, due either to reduced manipulative skills or the inability to put a name to the object, i.e., the problem was primarily a word finding difficulty.
Anaesthesia and Pain Tolerance
Localised areas of anaesthesia are not common, and are usually only found in persons with additional problems, e.g., stroke or alcoholism. However, staff at Arthur Preston Centre have noted high levels of pain tolerance in many residents. For instance, smokers can burn their fingers without complaining of pain. Similarly, patients have been known to lie on open sores with no apparent discomfort.
As deterioration occurs, persons with HD find a sudden ‘urgency’ in the need to empty the bladder. Poor control of sphincter musculature can result in some leakage of urine or, in the advanced stages of the disease, may result in total bladder emptying. Regular emptying of the bladder often helps resolve or control this problem (e.g., toileting before and after meals, or hourly visits.
Total bowel incontinence is rare, but is more prevalent in the later stages of HD, though it is difficult to determine to what extent this is due to inability to communicate.
Difficulty swallowing fluids and /or solids and even saliva is a common feature of the advanced stages of the disease. It can lead to choking, asphyxia and subsequent death. As noted earlier dysphagia also contributes to respiratory infection and inhalation pneumonia.