50 Stroke in Africa

William Howlett 25/09/18

50.1 Epidemiology

3 million of the 4.5 million annual stroke deaths occur in developing counries. The most uncertain estimates are those for large parts of SSA.

Prevalence in Hai, strokes amongst those >54 - 0.6% (men slightly more than women). Of those with a stroke, more than 50% had never had BP measured prior to stroke.

Incidence of Stroke in Tanzania in 2004, 212/100,000. This is higher than India, higher than Europe, higher than USA.

Mean age for Stroke in Tanzania 2007-13 = 52.5. Male:Female 1.8:1. HIV will account for Strokes in younger patients. In an HIV negative population, stroke mean age was in the 60’s.

50.2 Clinical Features

Usually unilateral weakness (almost 60%)

50.3 Pathology

Intracerebral haemorrhage risk is higher in SSA than in Europe. 20-35% rate of strokes were haemorrhagic.

Middle and small vessel disease seen on carotid ultrasound. This is different to a white population with predominately large vessel disease.

50.4 Risk Factors

The risk factors are the same as Europe.

The big difference is the prevalence of HIV. HIV serology increases your odds of stroke somewhere between 4-6. A previous stroke 5-9. HTN 2-3.

The other difference is Rheumatic Heart Disease.

One of the new concerns, is that hypertension prevalance is increasing in both urban and rural areas. Also is hyperlipidaemia. Also is obesity. Also is CKD.

Urban kilimanjaro prevalence of CKD, HTN, Hyperlipidaemia is the same as seen in USA

And then the next concern is that there is an urbanisation of Tanzania

Metabolic syndrome is seen in 20-30% of adults in Tanzania.

50.5 Management

The big difference is that they don’t thrombolyse, because they aren’t able to

50.6 Mortality

In KCMC:

  • Death in 1/4 of cases
  • Disability in 2/3 of cases
  • No disability in 10%

Similar seen in South Africa

Majority of mortality seen in the first year over the stroke.

Mortality:

  • 1 week - 10%
  • 1 month - 22%
  • 1 year - 40%
  • 3 years - 60%

Why do people die?

  • Aspiration

Who’s more likely to die?

  • conjugate gaze plus hemiplegia,
  • coma,
  • haemorrhage

50.7 Quality of Life

  • Worse QoL
  • More depression

This is worse with older age, worser strokes.

So Africa is no different to Europe.

50.8 Perceived Cause of Stroke

Stroke widely understood to be caused by demons, many believe it’s also caused by witchcraft. So people may go to traditional healers first.

William Howlett 25/09/18

Organism: clostridium tetani (anaerobic bacteria - gram positive rod, found in soil throughout the world)

It’s the spores in the soil, taken into the tissues as it’s an anaerobic.

No local reaction to the tetanus at the wound site. It’s the toxins that cause the problems:

  • Tetanospasmin this is the one in CNS. Through retrograde axonal flow
  • Tetanolysin

50.9 Tetanospasmin

It’s a GABA inhibitor. (GABA would usually inhibit alpha motor neurones)

Acts in spinal cord and brain.

So the toxin causes you to become stiff with some motor disorders.

50.10 Clinical Features/Course

  • Increased tone
  • Muscle rigidity
  • Muscle spasms

Extensors predominate over flexors.

The arms are not involved in tetanus. Tetanus attacks a very primitive GABA system

Recovery only occurs after new terminal synapses sprout in spinal cord/brain (4 weeks)

Incubation: 3-21 days. Usually one week

Progression to maximum disease: 2 weeks

Duration: 4 weeks

If you recover from tetanus you usually make a full recovery.

Facial symptoms:

  • Risus sardonicus (facial nerve)
  • Trismus (fifth nerve)

Patients can break bones and avulse tendons in the spasm

50.10.1 Classical Presentations

  • increased muscle tone
  • muscle spasms
  • autonomic nerveous system instability

You can rigid abdomen before epistotonus

Autonomic instability usually occurs towards the end of the second week.

50.10.1.1 Spasms

Variable - minutes to hours

Duratio - seconds to minute

Sensitive - to noise/dark/touch

Usually start 3 days after onset

Stops before stifness does

50.10.1.2 Autonomic Instability

Fever goes up. Sweating. BP labile. HR up or HR down.

50.10.1.3 Clinical Grading

Mild

Mod - short spasms, RR >30

Severe- prolonged spasms, RR>40, PR>120, apnoeac episodes

50.10.2 Atypical Presentations

  • Head and Neck - Lethal
  • Localized
  • Neonatal

50.10.2.1 Neonatal

  • Lack of handwashing
  • Unhydegic cutting of cord
  • home delivery

Usually caused by infection of umbilical stump

Usually occurs 6 days after birth

Mortality close to 90%

Morbidity 20-40% in survivors

50.11 Epidemiology

One million cases annually. Mostly India/S.E. Asia/SSA

Incidence is super rare. <1/1,000,000

80-90% cases follow a wound.

Age is a risk factor for fatality.

Predominantle a disease of children/neonatal

Main risk groups are neonates, children who missed vaccination. Older males who never got vaccination. Women often get vaccine in pregnancy.

50.11.1 Complications

ADD FROM SLIDES

50.11.2 sECONDARY INFECTIONS

Effectively pneumonia/UTI from catheter

50.12 Diagnosis

Is clinical

50.13 DDX

  • Meningitis
  • Rabies
  • Dystonia from psychotropic drug
  • Tetany
  • Seizures
  • Stiff Person Syndrome
  • Strychnine Poisoning

50.14 Management

Once tetanus toxin is bound, it can’t be reversed.

You have to support body until new synapses formed.

You want to prevent toxin production and you want to inhibit unbound toxin

Nursing care is in a quiet environment with no external stimuli.

Patient needs to be kept hydrated, will need an NG tube.

50.14.1 Plus

  • Metronidazole plus Ben Pen
  • Wound Care - debride and explore for foreign body

  • Immunoglobulin (but currently unavailable in N. Tanzania) (there are human forms and equine forms, both are expensive and difficult to source)

  • Treat spasms with diazepam plus others (phenobarbitone/chlorpromazine/magnesium sulphate)

  • Protect airway, may need early tracheostomy

  • Monitor for autonomic instability and may need labetalol

  • Careful NG Feeding

  • May need mechanical ventilation

LOADS FROM SLIDES TO ADD