Chapter 33

### Introduction

The disease is of long duration; to connect, therefore, the symptoms which occur in its later stages with those which mark its commencement, requires a continuance of observation of the same case, or at least a correct history of its symptoms, even for several years.

James Parkinson (1755–1824), An Essay on the Shaking Palsy

In general practice there are many neurological problems that present a diagnostic dilemma, with some being true masquerades for the non-neurologist. This applies particularly to various seizure disorders, space-occupying lesions in the cerebrum and the cerebellum, demyelinating disorders, motor neurone disorders and peripheral neuropathies.

The most common pitfall that occurs with neurological disorders is misdiagnosis, and the most common reason for misdiagnosis is an inadequate history. Failure to appreciate the neurological meaning of points elicited during the history is another reason for misdiagnosis.

Some very important neurological disorders are presented in this section: Parkinson disease, which is common and can be easily misdiagnosed, especially when the classic ‘pill rolling’ tremor is absent or mild; multiple sclerosis (MS), because it is difficult to diagnose initially; and acute idiopathic demyelinating polyneuropathy (Guillain–Barré syndrome), because it can be rapidly fatal if misdiagnosed. MS can masquerade as almost anything—‘If you don’t know what it is, think of MS.’

Another brain teaser for the family doctor is to diagnose accurately the various types of epilepsy. The most commonly misdiagnosed seizure disorders are complex partial seizures or atypical generalised tonic–clonic seizures (see CHAPTER 54).1 Even more difficult is the differentiation of real seizures from pseudo- or non-epileptic seizures. As a rule neurological conditions should be referred early for specialist management.

### Diplopia

The onset of diplopia (double vision) in adults is often acute, very distressing and invariably easy to diagnose. It is invariably binocular, which usually results from extraocular muscular imbalance or weakness. The type of binocular diplopia—vertical, horizontal or oblique—provides clues in identifying the affected muscle. Monocular diplopia is double vision that occurs in one eye when the other is covered. It arises from the eye itself.

Causes of binocular diplopia

• Ocular nerve palsies (3, 4 or 6); consider: CVA or TIA, tumour (orbital or intracerebral), aneurysm, diabetes mellitus, arteritis, head injury, ophthalmoplegic migraine (transient)

• Muscle tethering (e.g. blow-out orbital fracture)

• Multiple sclerosis (recurrent diplopia)

• Myasthenia gravis, hyperthyroidism (multiple muscle movement)

Diagnosis

Diplopia should be differentiated from blurred vision, which is like ‘ghosting’ on a TV screen.

###### Office tests

Test for double vision with each eye occluded. If diplopia persists, it is uniocular. If, however, double vision disappears when either eye is covered, there is a defect of one of the muscles moving the eyeball. Determine whether diplopia occurs in any particular direction of gaze. It ...

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

## Subscription Options

### Murtagh Collection Full Site: One-Year Subscription

Connect to a suite of general practice resources from one of the most influential authors in the field. Learn the breadth of general practice, including up-to-date information on diagnosis and treatment, as well as key clinical skills like communication.