Bulbar dysfunction

Motor neuron disease AIDS Subacute Motor dysfunction, muscle wasting with upper motor neuron signs bulbar dysfunction Possible immune mediated... 

When the VC is <50% predicted or MIP is <30% predicted, daytime ABG should be checked (46). Since accurate devices for measuring Pa02 and Paco2 noninvasively are now available, this is the recommended standard practice. Daytime Sa02 <95% may be associated with inspiratory or expiratory muscles, or bulbar dysfunction (10). In ALS, when the Sa02 cannot be normalized by NIV and mechanically assisted cough, a tracheostomy should be performed, if the bulbar dysfunction is severe (10). 

Bourke and colleagues (35,36) assessed the effect of NIPPV on QoL and survival in patients with amyotrophic lateral sclerosis (ALS) in a randomized controlled trial. ALS patients were assessed every two months and randomly assigned to NIPPV or standard care if they developed either orthopnea (with MIP <60% predicted) or symptomatic hypercapnia. The QoL outcome measures were the SF36 and the symptoms domain of the sleep apnea QoL index. In ALS patients without severe bulbar dysfunction, NIPPV improved survival and maintained QoL. The survival benefit from NIPPV in this group was much greater than that from currently available neuroprotective therapy. In patients with severe bulbar impairment, NIPPV improved sleep-related symptoms, but did not confer a large survival advantage. 

Whereas dysfunctional respiratory muscles may be supported to avoid respiratory failure, there are no effective noninvasive aids or substitutes for the bulbar-innervated muscles. Bulbar dysfunction leads to loss of speech and swallowing, resulting in aspiration and desaturation despite respiratory muscle aids. This is the only indication for tracheostomy among the NMD population (13). 

Most children are managed with NPPV (1,50). However, some require invasive ventilation through a tracheostomy. The main indications for a tracheostomy in children are airway abnormalities such as tracheobronchomalacia or tracheal stenosis, chronic disease of prematurity, and NMD (1,51,52). The indications for a tracheostomy are comparable to those of the adult population. They include the persistence of hypercapnia despite NPPV and additional measures such as daytime mouthpiece ventilation, aspiration, and bulbar dysfunction (53). In children, NPPV is more difficult to perform in those who might be 24-hour dependent, than in adults. Infants with primaiy alveolar hypoventilation (Ondine s curse) are preferentially ventilated by means of a tracheostomy (18). Tracheostomy ventilation favors airway inflammation (54) and may affect speech and language development (55). In children with progressive NMD, the decision of a tracheostomy has to be discussed on an individual basis, taking into account the familial environment and the parent s and child s perspective (52,56). In any case, sending children home with invasive ventilation is more difficult than when noninvasive ventilation is used (52). 

Clinically, mamba bites may not provoke a major local reaction. If neurotoxins are injected by the bite, clinical symptoms appear within minutes to hours. Clinical signs of impairment of neuromuscular transmission (ptosis, ophthalmoplegia, bulbar symptoms, or generalized weakness) dictate administration of antivenom (Ludolfph, 2000). For Elapidae (coral snakes) venom is known that is a potential neurotoxin and may cause paresthesias, weakness, cranial nerve dysfunction, confusion, fasciculations, and lethargy. Often mild local findings, diplopia, ptosis, and dysarthria are common early symptoms. Patients die because of respiratory paralysis. In these cases, early and aggressive... 

Typical symptoms of lithium intoxication are summarized in Table 2 [122-127]. The clinical picture of hthium intoxication is dominated by neuromuscular and cerebral symptoms in mild cases apathy, muscle weakness, tremor, and unsteady gait are seen. In more severe cases speech disturbances, myoclonic twitching, coma and convulsion can occur. Pulse irregularities and circulatory collapse may supervene. Lithium often causes T-wave flattening or inversion on the electrocardiogram, but clinically important cardiovascular effects are rare, with sinus-node dysfunction reported most often [123]. Residual neurological sequelae consisting of cerebellar dysfunction with ataxia, neuropathy and supra-bulbar symptoms are not unusual. 

The neuromuscular dysfunction is a very interesting phenomenon in this enigmatic condition. This condition presents with a classical triad of marked hypokalemia, TTX and severe quadraparesis. Quadraparesis may involve any muscle group, including the bulbar muscles and infrequently the cranial nerves, but the lower limbs are the most affected. Although the condition is often not life-threatening,... 

Bulbar muscle dysfunction should he evaluated in all patients with ALS. Apart from rating scales like the ALSFRS (101), one of the best ways to measure muscle dysfunction objectively is by comparing the MIC with the VC and the PEF with the PCF. The wider the gradient, the better the hulhar function (33,35). Bach has shown that in ALS, the ahdity to generate assisted PCF > 180 L/min and to have a high MIC to VC difference is associated with the capacity to use continuous NIV (36). However, when strictly tailored NIV and mechanically assisted cough do not prevent oxygen desaturation below 95%, aspiration is likely and tracheostomy should be offered (10). 

Along with hypoventilation, these alterations represent the most important problem from the patient s point of view (29). Severe bulbar dysfimetion and glottie dysfunction most commonly occur in patients with amyotrophie lateral selerosis (ALS), spinal muscle atrophy type 1, and the pseudobulbar palsy of eentral nervous system etiology (30). Inability to elose the glottis and vocal cords results in eomplete loss of the ability to cough and swallow. 

Patients with neuromuscular disorders (NMD) develop ventilatory failure because of a combination of dysfunctions of the inspiratoiy, expiratory, and bulbar-innervated muscles. Respiratory failure and the need for a tracheostomy are avoidable in most cases, using the approaches and interventions presented in this chapter. 

No6 HN (1988) The relationship of sibling reflux to index patient dysfunctional voiding. J Urol 130 1138-1141 Nonomura K, Kanno T, Kakizaki H et al (1999) Impact of congenital narrowing of the bulbar urethra (Cobb s collar) and its transurethral incision in children. Eur Urol 36 144-149... 

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