Late functional deterioration following paralytic poliomyelitis.

Many patients with previous poliomyelitis develop 'post-polio syndrome' (PPS) in which late functional deterioration follows a period of relative stability. The frequency with which PPS can be attributed to clearly defined causes remains uncertain. We reviewed 283 newly-referred patients with previous poliomyelitis seen consecutively over a 4-year period; 239 patients developed symptoms of functional deterioration at a mean of 35 (5-65) years after the paralytic illness. Functional deterioration was associated with orthopaedic disorders in 170 cases, neurological disorders in 35, respiratory disorders in 19 and other disorders in 15. Progressive post-polio muscular atrophy was not observed. Functional deterioration following paralytic polio-myelitis is common, and associated with orthopaedic, neurological, respiratory and general medical factors which are potentially treatable.

Enterovirus infection of the central nervous system of humans: lack of association with chronic neurological disease.

We have searched, using a sensitive nested-PCR, for enterovirus RNA in cerebrospinal fluid and post mortem central nervous system (CNS) tissue from patients with previous poliomyelitis with or without late functional deterioration, patients with motor neuron disease (MND), and control patients with other neurological disease or without neurological disease. Enterovirus RNA was detected in patients with previous poliomyelitis and MND, but also in control patients with and without neurological disease. Our results do not provide any evidence that such enterovirus infection is related to late functional deterioration in patients with previous poliomyelitis, which could be attributed to other medical conditions in most instances, and do not support the hypothesis that MND is associated with enterovirus infection of the CNS. Nucleotide sequence analysis of enterovirus RNA sequences detected indicated that enteroviruses detected were of the non-polio type.

Motor nerve conduction velocities calculated by F tacheodispersion in patients with anterior horn diseases.

F tacheodispersion, a new neurophysiological technique based on F waves, was used to determine the motor nerve conduction velocities in 16 patients with motor neuron disease and 19 patients with sequelae following paralytic poliomyelitis. The findings were compared to two age-matched groups, each consisting of 20 healthy volunteers. In each subject the F wave maximal, minimal, mean conduction velocities and the difference between maximal and minimal velocities of the ulnar and peroneal nerves were calculated. M response distal latency, amplitude and conduction velocity were also measured. There was a statistical significant slowing of one or more of the F wave estimated velocities in the absence of M response abnormalities in 31.3% of nerves in motor neuron disease group and in 27.3% of nerves in the poliomyelitis group; between 6.3% and 37.5%, of the nerves studied showed a significant change in the difference between maximal and minimal conduction velocities. Our results favour the presence of changes of motor fibre conduction properties in some patients with anterior horn diseases.

Respiratory insufficiency in neuronopathic and neuropathic disorders.

Twenty-nine patients with a neuronopathic or neuropathic disorder were referred for assessment of respiratory insufficiency between 1978 and 1994. Diagnoses included spinal muscular atrophy (6), chronic idiopathic demyelinating neuropathy (4), Vialetto-van Laere syndrome (3), hereditary motor and sensory neuropathy (3) and a miscellaneous group (5). We also describe seven patients with Guillain-Barré syndrome (GBS) who required long-term ventilatory support for over 6 months to 7 years after the initial illness. Respiratory insufficiency occurred as a consequence of respiratory muscle weakness, impaired bulbar function and restrictive lung defects. In some groups presentation was with progressive nocturnal hypoventilation culminating in acute respiratory failure. Five patients with GBS or chronic idiopathic demyelinating neuropathy were weaned from ventilatory support up to 18 months after the initial illness. The remaining 24 patients required continuous or nocturnal ventilatory support using intermittent positive-pressure ventilation (13), negative pressure ventilation (4), nasal-mask-delivered intermittent positive-pressure ventilation (4), nasal-mask-delivered continuous positive-pressure ventilation (3), mouthpiece-assisted ventilation by day (2) and rocking bed (1). None have been weaned from support after a period of ventilation ranging from one month to 10 years. Eight patients have subsequently died.

Neuroborreliosis as a cause of respiratory failure.

We report three cases of neuroborreliosis presenting with acute respiratory impairment. All the patients had encephalopathy and focal neurological signs with brain stem abnormalities in two. All three patients had respiratory arrest associated with progressive nocturnal hypoventilation or prolonged central apnoea. Tracheostomy and prolonged periods of ventilatory support were necessary in all cases and weaning was complicated by residual central respiratory disturbances. These cases emphasise that Borrelia infection should be considered in the differential diagnosis of unexplained respiratory failure.

Evidence for persistent enterovirus infection of the central nervous system in patients with previous paralytic poliomyelitis.

It has been suggested that late onset neurological deterioration after poliomyelitis may be due in some cases to persistent poliovirus infection of the central nervous system. In view of this, we decide to determine whether polioviruses and other enteroviruses can persist in the central nervous system. In a previous study, one of us (M.K.S.) reported serological evidence of persistent poliovirus infection of the central nervous system (CNS) in a proportion of these patients. We have now studied cerebrospinal fluid (CSF) from these patients for the presence of enterovirus RNA sequences using the polymerase chain reaction (PCR). Enteroviral RNA was detected in 3 of 24 patients with a clinical diagnosis of post-polio syndrome, but in none of 36 patients with stable poliomyelitis, and none of 36 patients with other neurological conditions of noninfective origin. All 3 patients in whom viral RNA was detected had high intrathecal levels of poliovirus-specific oligoclonal IgM bands. In a second study we examined formalin-fixed postmortem CNS tissue from 7 patients with a history of paralytic poliomyelitis. Enterovirus RNA was detected in tissue from the spinal cord from 3 patients, but not in the cerebral cortex. We are now conducting a larger prospective, blind study of patients with evidence of late deterioration. Analysis of the first 30 patients studied revealed the presence of enterovirus RNA in CSF of 1 of 4 patients with unexplained late-onset post-polio weakness, 1 of 6 with some evidence of clinical deterioration, but none of 20 without inexplicable signs of post-polio weakness. Enteroviral RNA was also detected in spinal cord from 2 of 3 patients who died from other causes during this study. These studies provide virological evidence that enteroviruses may persist in the CNS of man. Further study is required in order to understand fully the biological and clinical significance of these findings.

Multiple sclerosis presenting as late functional deterioration after poliomyelitis.

We describe five patients with previous poliomyelitis who developed multiple sclerosis (two laboratory supported definite and three clinically definite). The initial symptoms of functional deterioration developed a mean of 30 years following poliomyelitis. Initial functional deterioration was due to progressive limb weakness or impaired mobility and in three cases this led to an initial diagnosis of post-polio muscular atrophy. The clinical diagnosis became apparent with the subsequent development of characteristic clinical features, including optic nerve, brainstem, cerebellum, and spinal cord involvement. The occurrence of multiple sclerosis in these patients emphasises that late functional deterioration may be apparently unrelated to previous poliomyelitis. Furthermore, characteristic clinical features may be masked by the severe pre-existing neuromuscular and orthopaedic impairment leading to diagnostic delay and confusion with the ill-defined clinical syndrome of progressive post-polio muscular atrophy.

Use of the rocking bed in the treatment of neurogenic respiratory insufficiency.

We describe 53 patients who received ventilatory support with a rocking bed. Diagnoses included previous poliomyelitis (30), muscular dystrophy (12), motor neurone disease (4), adult-onset acid maltase deficiency (4) and a miscellaneous group (3). Patients presented with respiratory insufficiency characterized by diaphragm weakness, progressive nocturnal hypoventilation and/or acute or chronic respiratory failure. Domiciliary rocking beds were used by 43 patients for a mean of 16.0 years (range 1 month to 35 years). Most patients were able to breathe adequately by day when sitting or standing, but needed assistance by rocking bed for 6-11 h when lying down for sleep. The rocking bed was well-tolerated, and associated with both symptomatic relief and amelioration of arterial blood gas abnormalities. Seventeen of these 43 patients discontinued its use, either because of discomfort (9) or increasing respiratory insufficiency (8). The rocking bed is a valuable adjunct in the management of the respiratory insufficiency associated with neuromuscular disease.

Respiratory involvement in primary muscle disorders: assessment and management.

Eighty-four patients with primary disorders of muscle were referred for assessment of respiratory insufficiency between 1978 and 1991. The eventual diagnoses were: 'limb girdle syndromes' (18 patients), adult onset acid maltase deficiency (14), dystrophia myotonica (13), inflammatory disorders (10), congenital myopathies (nine), rigid spine syndromes (five), dystrophies (Duchenne (six), facioscapulohumeral (four), Becker (one)) and miscellaneous (four). Presentations were often insidious, with progressive nocturnal hypoventilation culminating in respiratory failure or arrest, recurrent respiratory tract infections, or obstructive sleep apnoea. Respiratory symptoms developed relatively early in patients with acid maltase deficiency and inflammatory disorders but parallelled the development of limb weakness in limb girdle, myotonic and congenital syndromes. Sixty-six patients received respiratory support for a median of 5 years (1-34 years) using various techniques of negative and positive pressure ventilation. Fourteen patients received short-term support for an episode of respiratory failure before being weaned, 51 required nocturnal domiciliary ventilation and one was dependent on continuous domiciliary support. Tracheostomy was performed in 32 patients and used for domiciliary nocturnal ventilation in 25. Twenty-eight patients have subsequently died.

Respiratory involvement in multiple sclerosis.

Respiratory complications occur in advanced multiple sclerosis (MS) but may also complicate acute relapses earlier in the disease. We present 19 patients with MS who developed respiratory complications at a mean of 5.9 (range 1-12) yrs after the onset of neurological symptoms. Fourteen patients developed severe respiratory insufficiency presenting with a combination of reduced forced vital capacity (FVC), hypoxaemia or hypercapnia (12 patients) and respiratory arrest (four patients). Two patients presented with apneustic breathing, one with paroxysmal hyperventilation, one with obstructive sleep apnoea and one with bulbar weakness leading to aspiration pneumonia. Respiratory muscle weakness was a major factor in 14 patients (predominantly diaphragm involvement in six), bulbar weakness in seven patients, impaired voluntary control in three and impaired automatic control in three. Twelve patients received mechanical respiratory support of whom seven have subsequently died. The methods of support used were intermittent positive pressure ventilation (nine patients), iron lung (three), cuirass (two) and rocking bed (one). Six patients were maintained on respiratory support until they died after intervals varying from 24 h to 6 yrs (mean 17.7 mths). Five patients received temporary ventilation for between 6 d and 42 d: of these four remain alive at up to 4 yrs and one died after 16 yrs. One patient remains on domiciliary nasal intermittent positive pressure ventilation (IPPV) after 1 yr.

Tracheostomy closure in restrictive respiratory insufficiency.

A retrospective study is presented of 31 patients who required ventilatory support via a tracheostomy for periods of one month to 27 years whilst in a tertiary referral centre for the care of patients with restrictive respiratory insufficiency. All patients underwent closure of a long-standing tracheostomy. Post-operative follow-up periods of up to 16 years are documented. The indications for and the complications of tracheostomy closure in patients with severe chronic restrictive respiratory insufficiency requiring long-term respiratory support are discussed. It is concluded that the benefits of operative tracheostomy closure outweigh the disadvantages in this unusual type of patient.

Peri-operative care in restrictive respiratory disease.

A total of 139 of 473 severely disabled, mainly ventilator-dependent patients required some form of surgery. Such patients require surgery more frequently than normal individuals, both because of their disability and because even minor unrelated disorders superimposed on permanent disability cause greater handicap. We report the peri-operative management and postoperative complications of 142 operations on 83 patients between 1982 and 1987. A simple inhalational anaesthetic technique was used; opioids and muscle relaxants were seldom given. Negative pressure ventilation was employed in the postoperative period when appropriate, and was combined with vigorous chest physiotherapy. There were three peri-operative deaths, but the overall death rate in the patients who underwent surgery was no greater throughout the study period than in those who did not require surgery. We believe that an aggressive surgical approach is appropriate in severely disabled, ventilator-dependent patients.

Central hypoventilation in a seven year old child following pertussis treated with negative pressure ventilation.

We report the case of a 7 year old girl who developed central hypoventilation following pertussis and who was treated by negative pressure ventilation using a new portable tank respirator. We believe this is the first reported case of central hypoventilation following pertussis successfully treated by intermittent negative pressure ventilation.

The late sequelae of poliomyelitis.

Progressive functional deterioration following poliomyelitis has been reported after a prolonged period of stability. We present follow up data on 209 patients; the period from the original illness to December 1985 or death was between two and 73 years (mean 33.9). One hundred and sixty-three (78 per cent) patients developed late functional deterioration. This was due to purely respiratory factors in 99 cases, new neurological signs in 20 cases, and orthopaedic problems in 17 cases; 31 patients deteriorated due to a combination of factors. The commonest cause of respiratory deterioration was the development of nocturnal alveolar hypoventilation, sometimes associated with late progressive scoliosis. Eighty-six patients needed respiratory support beginning between one year and 66 years (mean 28.5) after the acute illness. New neurological signs had a clearly defined cause in each of 20 patients. No cases of motor neurone disease or post-poliomyelitis muscular atrophy (PPMA) were identified. This series shows that late sequelae following poliomyelitis are common. There were no patients with functional deterioration after poliomyelitis in whom a clear underlying cause could not be shown. The major causes of deterioration may be treatable or avoidable, and in particular, those who develop chest infections or new respiratory symptoms should be treated with caution as respiratory failure may rapidly supervene.

Protein turnover in acid maltase deficiency before and after treatment with a high protein diet.

A patient with acid maltase deficiency was treated with a high protein diet for 7 months. Protein turnover expressed in terms of lean body mass was shown to be increased in this patient before the diet but was markedly reduced following the diet. The patient improved clinically whilst on the diet both subjectively and in terms of mobility, breathing and reduced peripheral cyanosis at rest.

Life-threatening respiratory failure due to a previously undescribed myopathy.

The case of a young man with a previously undescribed myopathy associated with polydactyly is reported. Although both limb girdles were affected, the major effect of the disease was upon the respiratory muscles leading to his presentation with life-threatening respiratory failure. A further feature was pronounced stiffness of the vertebral column and limb girdles, similar in some respects to the 'rigid spine syndrome'. Muscle biopsy appearances were unique but showed some similarities to both nemaline myopathy and myotonic dystrophy. Ventilatory assistance at night using a rocking bed led to a marked improvement and has enabled the patient to return to full-time employment.