Paralysis in the Body: The Differences of Localized and Generalized

Paralysis Definition

Paralysis is defined as the total or almost total loss of voluntary muscular movement. The term paralysis should not be used in the same way as paresis, as the latter indicates a mild muscular weakness.

Brief description

Paralysis is a symptom caused by a variety of conditions. Sensory perception of the paralysed body part is also diminished or lost in many cases. Paralysis is categorised in many different ways and is caused by a great variety of conditions, mainly of neurological nature. Any part of the body can be paralysed, depending on the cause,and the loss of voluntary control may or not be reversible.


Paralysis Classification

1. Depending on the extent

Localised paralysis: Affecting a particular part of the body. Examples of localised paralysis include Bell’s Palsy (face), paralysis of one hand or vocal cord paralysis.

Generalised paralysis: Paralysis affecting a wider area of one’s body. Typical types of generalised paralysis include:

  • Monoplegia: paralysis of one limb
  • Hemiplegia: paralysis of one side of the body (arm and leg)
  • Paraplegia: Paralysis of both legs and sometimes of the pelvic region
  • Tetraplegia: Paralysis of both arms and legs.

2. Depending on the duration

  • Temporary paralysis: Some instances of paralysis are temporary and reversible, like the facial paralysis caused by Bell’s palsy or a Guillain-Barre syndrome paralysis after treatment.
  • Permanent paralysis: Paralysis that is never reversed. Usually it is a result of serious injury, a major stroke or spinal cord injuries

3. Depending on sensory perception

  • Complete: A paralysis accompanied by sensory loss as well. the patient loses all ability to feel pain, heat, cold or any other sensation.
  • Partial: No sensory loss present.

4. Spastic or flaccid paralysis

  • Spastic paralysis: Even though a part of the body is paralysed, a spastic paralysis involves hypertonic muscles. Spastic hypertonia involves stiffened muscles that show resistance in passive movements. Uncontrollable spasms may be present as well. 
  • Flaccid paralysis: in this type of paralysis, muscles are weak, present no resistance to passive movement and may also be atrophic( having lost muscular mass).

Causes of paralysis

Paralysis, whether temporary or permanent, localised or widespread, can be caused by a variety of conditions. One of the causes affecting both young and old individuals involve major spinal cord injuries due to traumatisation. Moreover, conditions affecting the muscles themselves and the nervous system are responsible for causing paralysis.


Trauma:

Depending on the level of the spinal cord injury, different types of paralysis occur.The criteria determining which part of the body will be affected are the spinal vertebrae involved in the injury. There are 7 cervical vertebrae (C1-7), located at the neck, followed by 12 thoracic ones across the thorax (T1-12). The next 5 vertebrae are the lumbar vertebrae (L1-5) and finally, 5 sacral vertebrae leading to the coccyx (S1-5).

  • Cervical injuries: injuries to the cervical region of the spinal column cause tetraplegia and diaphragm weakness. Patients lose control of their arms and legs and need assistance breathing (ventilator). 
  • Thoracic injuries: Patients experience paralysis in their legs, while retaining fully functional upper limbs. Bowel and bladder function is also impaired.
  • Lumbar injuries: While injuries in the lumbar region do not cause total paralysis,they limit the ability to move one’s hips, knees and thighs.
  • Sacral injuries: not involved in the appearance of paralysis. Such injuries cause bowel and bladder problems as well as impotency. 

Muscular conditions causing paralysis:

  • Muscular dystrophy: Duchenne’s muscular dystrophy, congenital dystrophy and other types.
  • Polymyositis 
  • Dermatomyositis

Conditions of the nervous system causing paralysis:

  • Multiple sclerosis
  • Guillain-Barre syndrome
  • Adrenoleukodystrophy
  • Strokes
  • Amyotrophic lateral sclerosis or Lou Gehring’s disease
  • Parkinson’s disease
  • Poliomyelitis

Other causes of paralysis:

  • Tick bite
  • Botulism

Diagnosis and Treatment

Given the wide range of conditions causing paralysis, there is a variety of diagnostic tests carried out to determine its cause. A doctor will perform  a detailed clinical examination, take a patient’s medical history and carry out tests involving MRIs, CT-scans, muscle biopsy and blood tests among others. Treatment depends on the underlying condition.