• Risk benefit analysis of the surgery and the anesthetic risk.
• Neurological examination for scoring neuromuscular disease symptoms and severity
• Electrocardiogram
• X-ray of the thorax
• Echocardiography
• Pulmonary function tests
• Arterial blood gas analysis
• Serum electrolyte, creatine kinase and myoglobin analysis
• Measurement of inspiratory muscle strength

Motoneuron diseases (e.g. post-polio syndrome, spinal muscular atrophy, ALS)

1. Non-depolarizing muscle relaxants are suggested but complications may arise due to drug sensitivity.

2. Using a centrally acting drug (i.e. baclofen and diazepam) or dantrolene after surgery is often indicated to control postoperative spasticity.

Peripheral neuropathies (e.g. Charcot Marie Tooth)

1. Risks and benefits of regional or general anesthesia should be examined on a case-by case basis with a clear diagnosis and knowledge of the stage of the disease.

2. CMT may have increased sensitivity to thiopental.

Disorders of neuromuscular transmission (e.g. myasthenia gravis, Lambert-Eaton, etc.)

1. Medication administered pre-operatively should be minimized so that respiratory function is not depressed.

2. Other medications such as antibiotics, antiarrhythmics, Ca 2+ channel blockers, and psychotropic agents may need to be discontinued prior to surgery.

3. Oral anticholinesterases should be taken until six hours before anesthesia is administered and then should be given intravenously only if necessary because they might hinder muscle relaxation.

4. Volatile anesthetics and succinylcholine can be used, but should be avoided whenever possible. Dosage must usually be significantly reduced.

Progressive muscular dystrophies (e.g. Duchenne, Becker,myotonic dystrophy, etc.)

1. Risks are determined by any respiratory and cardiac conditions, independent of severity of muscle symptoms.

2. Inhalation anesthetics, succinylcholine and anticholinesterase drugs aren’t recommended. They may provoke malignant hyperthermia, severe muscle breakdown (rhabdomyolysis), and heart rhythm disturbances. The dosages of all other anesthetics have to be carefully chosen as all of them decrease cardiac function. In children with muscular dystrophy, cardiac function is often already compromised especially at more advanced stages of the disease.

3. Non-depolarizing muscle relaxants like vecuronium, atracurium, and mivacuro-ium can be used safely albeit at a reduced dose.

4. The dysfunction of smooth muscle and platelets may cause increased blood loss. Therefore, hypotensive anesthesia is recommended.

5. Moderate to lengthy surgical procedures are indications for vascular monitoring and laboratory testing during surgery. Intensive care stays after such surgery are routine.

6. Succinylcholine may aggravate the myotonia in myotonic dystrophy, Nuvacurium, atracurium and vecuronium may be used for muscle relaxation.

Metabolic myopathies (e.g. acid maltase deficiency, lipid storage myopathies, etc.)

1. Outpatient surgery may not be an option.

2. Plans should be made for metabolic monitoring before, during and after surgery with glucose infusion to prevent hypoglycemia.

3. Because of the potential for myoglobinuria, adequate hydration and a diuretic may be used to avoid acute renal failure.

Mitochondrial myopathies

1. Great variabilitymakes anesthetization very difficult and most drugs have depressant effects on mitochondrial functon.Caution must be taken.

2. Due to risks of total cardiac block in people with mitochondrial myopathies, an external pacemaker should be present in the operating and recovery rooms.

3. People with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) and/or MERFF (myoclonus epilepsy with ragged red fibres) may require anticonvulsive and symptomatic therapy.

4. To prevent hypo and hyperglycemia, stringent glucose monitoring will be needed before and after surgery.

5. Excessive pre-operative fasting, metabolic stress and infusion of Ringer’s lactate should be avoided.

Non-Dystrophic myotonias and periodic paralysis (e.g. Myotonia fluctuans, paramyotonia congenital, etc.)

1. Make sure the anesthesiologist is aware that you have a non-dystrophic myotonia (especially if you have no obvious outward signs of the condition) so that the correct medications can be used during surgery.

2. Depolarizing muscle relaxants should not be given because they induce jaw muscle spasms and stiffness in respiratory and other muscles that make intubation and mechanical ventilation difficult.

3. Maintaining adequate potassium and glucose levels and keeping patient warm are important in preventing periodic paralysis attacks.

4. Despite the consequence of periodic paralysis, regional anesthesia, whenever feasible, seems to be preferred.

5. Succinylcholine may cause generalized muscle spasms that resemble malignant hyperthermia.

Malignant hyperthermia

1. Predisposition to life threatening crises is usually triggered by volatile anesthetics and exacerbated by succinylcholine.

2. Rapid infusion of dantrolene is necessary when malignant hyperthermia occurs.

3. Safe drugs: propofol, opioids, nitrous oxide, barbiturates, benzodiazepines and all local anesthetics.

Congenital myopathies

1. Non-depolarizing muscle relaxants used sparingly to avoid post-operative respiratory failure due to the pre-existing muscle weakness.

2. May be susceptible to malignant hyperthermia.