Hydrocephalus

Original Editor - Shaimaa Eldib Top Contributors - Shaimaa Eldib, Srishti Banerjee and Kim Jackson One Page Owner - Srishti Banerjee as part of the One Page Project

Introduction

Hydrocephalus is an abnormal build-up of cerebrospinal fluid(CSF) within and around the brain, which can due to excess fluid production, obstruction to its flow, and inadequate absorption[1] If left untreated, the excess fluid can cause increase the pressure put on the skull and brain, which can be damaging[2].

Causes

The etiology of hydrocephalus can be congenital or acquired. Hydrocephalus due to any obvious external cause is termed as congenital hydrocephalus whereas hydrocephalus secondary to any condition such as hemorrhage is known as acquired hydrocephalus. The most common cause of acquired hydrocephalus in infants is hemorrhage due to prematurity. In addition to this, the other causes include neoplasm, an infection most often bacterial meningitis, intrauterine infections with enterovirus, lymphocytic choriomeningitis, toxoplasmosis, and CMV. Infantile hydrocephalus is associated with certain medications taken during pregnancy such as anti-depressants, misoprostol, and metronidazole. hydrocephalus which is not caused by any of the above-mentioned extrinsic causes it is regarded as congenital hydrocephalus with some underlying genetic pathology. X-linked hydrocephalus is associated with aqueductal stenosis, which forms one of the most common hereditary forms of hydrocephalus affecting 10% of males with isolated idiopathic hydrocephalus. In addition to these causes, neural tube defects also cause hydrocephalus[3].

Classification.

Classification of hydrocephalus has always been controversial , the first first attempt for the classification of hydrocephalus was made by Walter Dandy in 1913. The current classification with relation to the latest evidences hydrocephalus can be classified as communicating hydrocephalus and non communicating hydrocephalus.

Communicating hydrocephalus is further divided into obstructive and non obstructive types.

Communicating hydrocephalus results when there is impedance of cerebrospinal fluid after it exits the ventricles. Communicating hydrocephalus can be obstructive in nature where there is obstruction at some point between basal cisternae and arachnoid granulations. This obstruction can be due to conditions like subarachnoid hemorrhage , meningitis , congenital or acquired pathologies[4][5][6].

Location of the obstruction and corresponding causes of obstruction[7]

Location Cause
Lateral, 3rd and

4th ventricles

Intraventricular haemorrhage
3rd ventricle at foramen

of Monro

Colloid cyst
3rd ventricle Tumours
Cerebral aqueduct Aqueduct stenosis

Tumours

4th ventricle Dandy Walker malformation

Tumours

Impaired absorption at the

arachnoid granulations

Subarachnoid haemorrhage

Trauma

Meningitis

Non obstructive communicating hydrocephalus includes normal pressure hydrocephalus which can be idiopathic or secondary following trauma[8].

Non communicating hydrocephalus occurs when there is intra ventricular obstruction of CSF flow , therefore non communicating hydrocephalus is always of obstructive type. This obstruction in the CSF flow can be due to conditions such as TORCH INFECTIONS[1] or congenital anomalies, The sites of obstruction includes Foramen of Munro and cerebral aqueduct[9].

Pathophysiology - Change in CSF dynamics.

With the development of hydrocephalus, there is an alteration in CSF dynamics. The CSF exchange between the lateral ventricles and the third ventricles is compromised. With the development of hydrocephalus the Foramen of Munro undergoes dilation. Both the lateral ventricle and the third ventricle becomes monoventricule , however the cerebral aqueduct retains its function. Also there is exaggerated motion of CSF through cerebral aqueduct. In addition to this CSF pulsatility( i.e with every heart beat the arterial blood volume increases briefly and venous blood and CSF are pushed out of the cranium which leads to the pulsatile flow of CSF)is also disturbed. These changes lead to compromise in the unidirectional flow of CSF from the site of production to the site of absorption[10].

Clinical features[7]

Clinical features of hydrocephalus widely vary according to the age of the patient and the rate of progression.

  • Clinical features of hydrocephalus before the closure of the cranial sutures (<2 years of age ) include macrocephaly, increasing head circumference of the head , sunsetting sign, distend scalp veins , developmental delay, poor feeding and regression.
  • After the closure of cranial sutures , the acute presentation includes, headache, vomiting, drowsiness , papillodema and coma in extreme cases.
  • Chronic presentation and clinical features of normal pressure hydrocephalus include incontinence cognitive impairments and gait disturbances

Medical Management

Babies born or children who have developed with hydrocephalus usually require swift treatment to reduce the pressure on their brain. If the condition is not treated, the increase in pressure will damage the brain. Both congenital and acquired hydrocephalus can be treated with shunt surgery or neuroendoscopy[11].

Shunt Surgery

Shunt surgery consists of inserting a thin tube (a shunt) in the brain, which is used to remove excess fluid from the brain. The fluid passes through the shunt to a different body part, usually the abdomen (the belly) area, and is then absorbed into the blood stream. The shunt has a valve for the control fluid flow and to make sure it drains gradually and not too quickly, the valve can be felt as a lump under the skin of the scalp[11],[12]. Shunt surgery is carried out by a specialist in surgery of the brain and nervous system (neurosurgeon). A general anaesthetic will be given before the operation so that the child will be asleep throughout the procedure, which usually takes between one to two hours. After the operation, a child will need to stay in the hospital for a few days to recover. Once the shunt has been fitted, there is a risk that there could be shunt malfunction, such as blockage or infection of the shunt, leading to the need for essential additional treatment[11],[12]. Some symptoms of shunt malfunction are headaches, sickness, confusion, drowsiness, redness, increased temperature, neck stiffness, abdominal pain, and irritability[11].

Endoscopic third ventriculostomy (ETV)

ETV involves creating a hole in the bottom of the brain, which allows trapped fluid to discharge to the surface of the brain where it can then be absorbed. However, an ETV is not suitable for everyone, but it may be a possible treatment option if the excess fluid in the brain is resulting from a blockage, known as obstructive hydrocephalus. The fluid will then be able to drain out via the hole and avoiding any blockage from occurring. A general anaesthetic is given prior the operation and the neurosurgeon will then create a small hole the skull of the child and use a small camera device (endoscope) to look inside brain chambers. A small hole will then be created inside the brain with the help of the endoscope. This procedure will take approximately one hour[11],[12].

There is reduced risk of infection following ETV surgery compared with the shunt, but there is still a chance that the ETV’s may block months or years after surgery. However, there are some risks associated with ETV, such as hole closure, inability of the brain to absorb excess fluid, or bleeding in the brain (usually minor)[11]

Physiotherapy Management

Regardless of the different surgical management, children with hydrocephalus still have some disabilities. Therefore, early involvement with physiotherapists via different methods of rehabilitation is essential, whether surgical or non-surgical management is required. Additionally, successful shunting is usually related to more obvious and rapid improvements in rehabilitation efforts[13]. Specific treatment procedures are numerous, functional training for activities of daily living; therapeutic exercise; manual techniques such as mobilization and stretching; and therapeutic modalities[14].

Physiotherapy goals are aimed at:

  • Improving functional skills and reducing secondary impairment, such as obesity, contractures, and fractures, which could delay developmental skills. Furthermore, physiotherapists can work with children in their home and in the hospital or clinic, depending on their medical conditions and age[15].
  • Motor control (co-ordination of muscles and limbs), learning theories, and development are factors that contribute to occurrence of motor behaviour (how the muscles and limbs react to movement, control, development, and learning). These factors include not only the central nervous system (brain and spinal cord) as the driving force, but also biomechanical (human movement principles), psychological, social, and environmental components[14].
  • Teaching and practicing skills under these theories is task-oriented (specific to everyday movements e.g. sitting to standing), which should be intermittent and repetitive. A high level of learning occurs via a child’s problem solving instead of by the therapist's hands-on facilitation. It is also important that emphasis is placed on family centred care and treatment in natural environments.
  • The mutual goal is usually to increase functional activity, which in turn, decreases disability[14].

These goals should be achieved by[16]:

  • Promoting physical milestones of achievement such as sitting, crawling, standing
  • Optimising mobility independence
  • Improving balance and coordination via exercise
  • Stretching tight muscles via exercise
  • Strengthening weak muscles via exercise
  • Increasing quality of life and confidence
  • Improving endurance and exercise tolerance

References

  1. SHEPHERD, R.B., 1995. Physiotherapy in Paediatrics. 3rd ed. Oxford: Butterworth Heinemann.
  2. SOCCI, D.J., BJUGSTAD, K.B., JONES, H.C., PATTISAPU, J.V. and ARENDASH, G.W., 1999. Evidence that oxidative stress is associated with the pathophysiology of inherited hydrocephalus in the h-tx rat model. Experimental Neurology. January, vol. 155, no. 1, pp. 109–117.
  3. Tully HM, Dobyns WB, Infantile hydrocephalus: A review of epidemiology, classification and causes, European Journal of Medical Genetics (2014), http://dx.doi.org/10.1016/j.ejmg.2014.06.002
  4. Rekate HL. A consensus on the classification of hydrocephalus: its utility in theassessment of abnormalities of cerebrospinal fluid dynamics. Childs Nerv Syst. 2011 Oct;27(10):1535-41.
  5. Rekate HL. A contemporary definition and classification of hydrocephalus. SeminPediatr Neurol. 2009 Mar;16(1):9-15.
  6. Mori K, Shimada J, Kurisaka M, Sato K, Watanabe K. Classification of hydrocephalus and outcome of treatment. Brain Dev. 1995;17:338–348.
  7. 7.0 7.1 Robert Corns, Andrew Martin, Hydrocephalus, Surgery (Oxford),Volume 30, Issue 3,2012, Pages 142-148, ISSN 0263-9319, https://doi.org/10.1016/j.mpsur.2011.12.010.
  8. Kiefer M, Unterberg A.The differential diagnosis and treatment of normal-pressurehydrocephalus. Dtsch Arztebl Int. 2012 Jan;109(1-2):15-25
  9. Vijetha V. Maller, Richard Ian Gray, Noncommunicating Hydrocephalus, Seminars in Ultrasound, CT and MRI, Volume 37, Issue 2, 2016, Pages 109-119, ISSN 0887-2171, https://doi.org/10.1053/j.sult.2015.12.004.(http://www.sciencedirect.com/science/article/pii/S0887217115001481)
  10. Shinya Yamada, Erin Kelly, Cerebrospinal Fluid Dynamics and the Pathophysiology of Hydrocephalus: New Concepts, Seminars in Ultrasound, CT and MRI Volume 37, Issue 2, 2016, Pages 84-91, ISSN 0887-2171,https://doi.org/10.1053/j.sult.2016.01.001(http://www.sciencedirect.com/science/article/pii/S0887217116000020)
  11. 11.0 11.1 11.2 11.3 11.4 11.5 NHS CHOICES., 2014. [viewed 15 October 2014] Available from: http://www.nhs.uk/Conditions/Hydrocephalus/Pages/Treatment.aspx
  12. 12.0 12.1 12.2 MAYO CLINIC., 2014. [online]. [viewed 17 October 2014] Available from: http://www.mayoclinic.org/diseases-conditions/hydrocephalus/basics/treatment/con-20030706
  13. BONTKE, C.F., ZASLER, N.D. and BOAKE, C. 1996. Rehabilitation of the head-injured patient. New York, NY: McGraw-Hill.
  14. 14.0 14.1 14.2 INSTEP PHYSICAL THERAPY., 2014. [viewed 15 October 2014] Available from: http://www.instepphysio.ca/Neurorehabilitation/Neurorehabilitation/a~3553--c~343920/article.html
  15. KARIMZADEH, P. 2012. Management of hydrocephalus. Hydrocephalus [online]. Available from: http://www.intechopen.com/books/hydrocephalus/management-of-hydrocephalus-
  16. MANCHESTER PHYSIO., 2014 [viewed 15 October 2014] Available from: http://www.manchesterphysio.co.uk/what-we-treat/paediatric-physiotherapy/hydrocephalus.html