Dropped Head Syndrome associated with Motor Neurone Disease

Original Editor - Eugenie Lamprecht Top Contributors - Eugenie Lamprecht  

Introduction

Neck and back muscles.jpg
Dropped head syndrome (DHS) is a rare condition characterized by severe weakness of neck extensors and may associate with weakness of shoulder girdle and proximal arm muscles. This occurs as a result of several neurological, neuromuscular, muscular, and other causes[1].

Clinical presentation

The typical clinical presentation of DHS refers to a “chin on chest” posture due to neck extensor muscular weakness. This makes it difficult for individuals diagnosed with DHS to keep their head in an upright position while walking, standing, and talking. Many individuals use their hands to support their chin as a result.

This may also lead to dysphagia, dysarthria, and social implications.[2]

Pathological Process

The dropped head syndrome occurs among 1-3% of individuals diagnosed with Amyotrophic Lateral Sclerosis (ALS) or sometimes referred to Motor Neurone Disease. Even though this is quite a rare manifestation of ALS but bears a poor prognosis. Dropped Head Syndrome is commonly also associated with bulbar palsy and/ or weakness of the upper limbs.[2]

Research suggests that the development of DHS in ALS may be due to the degeneration of paraspinal anterior horn cells leading to atrophy of affected muscles. It is also progressive of nature and easy to diagnose, as widespread denervation is evident on EMG and mild CK elevation is common.[2]

Difficulty with swallowing, speaking and/ or breathing has also been associated with individuals with DHS and ALS. Individuals may also struggle with neck pain and impairment in ADLs such as dressing, eating, showering, etc.

Other neurological conditions that may lead to DHS include

  • Parkinson disease
  • multiple system atrophy,
  • cervical dystonia,
  • postpolio syndrome,
  • cervical myelopathy,
  • chronic inflammatory polyneuropathy (CIDP),
  • neuromuscular causes include myasthenia gravis (MG),
  • Lambert-Eaton myasthenia syndrome (LEMS),
  • Muscular causes include primary inflammatory such as polymyositis,
  • Scleromyositis,
  • Isolated inflammatory axial myopathy,
  • Primary non-inflammatory conditions (nemaline myopathy, mitochondrial myopathy, and congenital myopathy)
  • Isolated neck extensor myopathy (INEM).[2]

Diagnostic Procedures

In order to diagnose DHS, the healthcare professional should rule out structural causes of the cervical spine first.

It is also important to distinguish between neuromuscular (NM) causes and non-neuromuscular (non-NM) causes;

  • NM causes: a significant weakness of neck extensors.
  • Non-NM causes: dystonic anterocollis developing due to an imbalance of neck muscle tone producing neck flexion as a result of repetitive muscle contractions.

Previous medical & family history

  • Any previous onset or occurrence of isolated/ diffused neck weakness.
  • Any cranial and/ or bulbar muscle involvement.
  • Any respiratory muscle weakness or symptoms.
  • Family and developmental Hx.

Physical examination

  • Upper and/ or lower motor signs
  • Muscle atrophy
  • Skin changes
  • Ocular or bulbar weakness
  • Facial weakness
  • Selective weakness patterns
  • Pelvic girdle weakness.

Imaging

  • X-rays to rule out fractures, arthritis and kyphosis.
  • MRI & CT scan to review soft tissue, fatty infiltration, oedema, inflammation and muscle atrophy.
  • Needly study of facial -, tongue -, sternocleidomastoid -, trapezius -, cervical and thoracic spinal muscles.

Management

Pharmacologic/Surgery

Pharmacologic and conservative protocols should always be trialled before surgery is suggested for most neuromuscular disorders.

Isolated neck extensor myopathy (INEM) will be treated with a course of immune-modulating therapy like corticosteroids after an individual was assessed by a rheumatologist or neurologist first and cleared from alternative diagnosis or causes (autoimmune or neuromuscular).

If this approach fails, subaxial fusion surgery, across the cervicothoracic junction, may be suggested. Fusion from C2-T2 preserves movement of the upper Cx spine and Tx spine, to prevent excessive Tx kyphosis, often observed in individuals with DHS.[3]

Support/ a brace

Support and braces aim to maintain an upright gaze, correct postural alignment, encourage comfort with ADLs, while also facilitating proper swallowing and feeding, as well as breathing.

Even though braces may cause skin irritation, further weakening of neck muscles, it should be initiated early to prevent deformity, compression, muscle contractures, worsening of myelopathy, neurological symptoms, and disability.

Options vary from hard and soft collars, corsets, vests, and wheelchair headrests.[3][4]

Physiotherapy management

Physiotherapy is mainly supportive management in DHS, by aiming to slow down the progression of the condition and maintain current function. [4]

Treatment includes:

  • Balance retraining
  • Education
  • Manual therapy & pain management
  • Postural retraining
  • Chest PT -  Important to assess pt’s ability to create forceful FET and sufficient inspiration volumes. It’s also important to monitor your patient’s risk for aspiration.
  • Range of Motion exercises -  prevents stiffness and shortening of neck flexors.
  • Strengthening exercises of the neck, UL's, LL's and trunk muscles.

References

  1. Lorenzoni PJ, Lange MC, Kay CS, Almeida LG, Teive HA, Scola RH, Werneck LC. Dropped head syndrome in motor neuron disease. Arquivos de neuro-psiquiatria. 2006 Mar;64(1):118.
  2. 2.0 2.1 2.2 2.3 Burakgazi AZ, Richardson PK, Abu-Rub M. Dropped head syndrome due to neuromuscular disorders: Clinical manifestation and evaluation. Neurology international. 2019 Sep 18;11(3).
  3. 3.0 3.1 Stephen Ornstein. Neck Solutions [Internet]. Dropped Head Syndrome Results In Neck Pain, Trouble Eating & Interferes With Vision. Available from: https://www.necksolutions.com/dropped-head-syndrome/. [Accessed: 9/8/2020]
  4. 4.0 4.1 Young CA, Baker AD. Evaluating the Effectiveness of Physiotherapy for Dropped Head Syndrome: A Review of The Evidence and Case Series Presentation For This Unusual Phenomenon. In Orthopaedic Proceedings 2017 May (Vol. 99, No. SUPP_10, pp. 12-12). The British Editorial Society of Bone & Joint Surgery.