PARAPLEGIA

The term paraplegia or paraparesis denotes complete or partial weakness of both lower limbs, respectively. Clinically, it may be further classified according to duration (acute or subacute) and type of lesion (spastic or flaccid).

Etiology of paraplegia is best classified according to the site of lesion (Table 18.38).

TABLE 18.38: Causes of paraplegia in childhood

Spastic paraplegia

• Cerebral (rare)

Sagittal sinus thrombosis

Cerebral palsy

• Spinal cord lesions

Inflammatory: Acute transverse myelitis

Compressive: Pott's spine, extradural abscess

Tumors: Spinal tumors, secondaries

Traumatic: Spinal cut-injury section, hematomyelia Vascular: Arteriovenous malformations Anatomical: Syringomyelia, diastematomyelia Degenerative: Familial, post-ARV vaccination

Toxic: Lathyrism, subacute combined degeneration

Flaccid paraplegia

• Spinal shock

• Anterior horn cell disease: Poliomyelitis, SMA

• Vertebral deformities (Nerve compression)

Kyphoscoliosis, lordosis

Collapse of vertebral body - traumatic, pathological

• Peripheral neuropathies

Guillain-Barre syndrome

Others (Ch. 18.18.2)

• Myopathies

Duchenne muscular dystrophy

Others (Ch. 18.18.4)

• Miscellaneous

Autonomic neuropathy: (Riley-Day syndrome)

Hysteria

SMA: Spinal muscular atrophy is mainly proximal in myopathies and distal in neuropathies.

Step II. Whether sensory involvement is present?

Presence and level of sensory involvement, e.g. anesthesia or paresthesia indicates site of spinal cord injury[‡‡‡‡‡‡] in spastic paraplegia and peripheral neuropathy in flaccid paraplegia. Spinal cord lesions are usually associated with anesthesia below the level and paresthesia at the level. Presence of root pains indicates nerve compression (compressive myelopathy), as seen in extramedullary tumors or Pott's spine.

*While sensory examination assists to identify the spinal segment of lesion, these spinal segments do not correspond to vertebral level. For identification of vertebral lesion subtract 1 from cervical spine levels (e.g. C₈ = 7^th cervical vertebrae), subtract 2 from T_1-g lesions (T₈ = 6^th thoracic vertebrae) and subtract 3 for T_{9 12} lesions (T₁₂ = 9^th thoracic vertebrae). Lumbar spinal segments L₁₂, L₃₁ L₅ correspond with 10^th,11^th and 12^th thoracic vertebrae. Sacrococcygeal spinal segments originate from 1^st lumbar vertebrae.

Step III. Whether bladder is involved?

Urinary bladder is frequently involved in paraplegia. Spastic bladder, i.e. low capacity, contracted bladder with frequent reflex emptying and loss of voluntary control indicate spinal lesions above the level of L_1-2. Bladder in LMN lesions or spinal shock may be either distended with over-flow incontinence (atonic bladder) or empty reflexly at regular intervals without voluntary control (autonomic or autonomous bladder).

Step IV. What is the onset, duration and progression of weakness?

Acute paraplegia of a few minutes or hours duration is mainly vascular or traumatic; while more insidious lesions developing over a few days may be due to transverse myelitis, infective spinal lesions, poliomyelitis or Guillain-Barre syndrome.

Paraplegia, evolving over a few weeks or months indicates intraspinal space occupying lesions (tumors, abscesses, hematoma) or compressive myelopathy, syringomyelia and degenerative disorders of spinal cord. Peripheral neuropathies and myopathies, involving lower limbs also present as slowly developing paraparesis.

Step V. Paraplegia is in flexion or extension?

Paraplegia in flexion is characterized by predominant flexor weakness and spasticity in lower limbs and indicates generalized or complete involvement of spinal pyramidal tracts. Paraplegia in extension indicates incomplete pyramidal tract lesions.

Step VI. Search for spinal deformities, e.g. obvious neural tube defects, tuft of hair/dimple or sinus (Spina bifida occulta), tenderness over spine (compressive myelopathy, e.g. in Pott's spine).

Diagnostic investigations in paraplegia depend on the suspected cause and site of lesion. Spinal MRI is essentia

in all cases of spastic paraplegia, though spinal X-rays and CSF examination may be helpful in some cases. A positive Queckenstedt test, xanthochromic CSF and elevated proteins indicate spinal block (Froin syndrome), usually due to extramedullar tumors.

All cases with acute flaccid paraplegia should be reported for AFP surveillance, discussed below. and investigated accordingly. Chronic cases need EMG, muscle biopsy and serum CPK levels to exclude myopathies and NCV for neuropathies, as discussed in next chapter. Important d/d for common causes of acute flaccid paralysis in Indian children is given in Table 10.36.

Management of a paraplegic child aims to prevent secondary complications till primary cause is treated or the patient recovers spontaneously. Important steps in general care of a paralytic child includes: (a) maintenance of good nutrition, (b) care of the back/bowel and bladder, (c) physiotherapy and orthotic support, (d) prevention and treatment of intercurrent infections, e.g. pneumonia, (e) rehabilitation, and (f) psychological support.

Acute flaccid paralysis (AFP) surveillance is a critical component of national polio surveillance project since 1997, “to detect all cases of wild polio virus disease and eliminate remaining foci of polio transmission”.

What is AFP? AFP is defined as “any illness presenting with acute onset of flaccid paralysis in a child lt;15 years, for which no obvious cause such as trauma or electrolyte imbalance is found or a person of any age, with clinical suspicion of polio”. Generally, AFP of lt; 4 weeks is considered as acute.

Why all cases of AFP should be investigated? Since it is often difficult to exclude the diagnosis of poliomyelitis in a suspected case at the time of presentation, it is essential to investigate each case of AFP, to ensure that all cases are detected, reported and investigated and no case is missed out.

Components of AFP surveillance include: (a) reporting,

(b) investigation of suspected case, and (c) outbreak­control measures after suspected case report.

All Field reporting units, e.g. district health centers or pediatric units of major hospitals must collect and send weekly reports of suspected case/s. Ifno case is seen during reporting week, the report has to be sent as 'nil or zero report' Investigation of suspected AFP case includes: (a) imme­diate reporting to the designated person, (b) detailed data collection and Line-listing of all reported cases with a unique EPID number, to prevent duplication of reports,

(c) collection of stool cultures for virus isolation, as specified earlier.

A stool sample should be collected (~8 gm or thumb size) from all cases presenting within 14 days of the onset of weakness (as early as possible) and transported to designated laboratory in ice pack (reverse cold-chain) under AFP surveillance program. A rectal swab may be collected from patients who do not pass stool within 24-48 hours of hospitalization.

Classification of an AFP case: All cases of reported AFP are classified after detailed epidemiological and viral studies as Polio or non-polio cases.

An AFP case is confirmed as poliomyelitis only if: (a) wild polio virus isolated from stool sample, or in absence of adequate stool sample, (b) cases continues to have residual weakness after 60 days of onset or 60 days-follow-up not available due to death or absence and expert review concludes that these cases could not be discarded as non-polio based on available data.

18.18